const Main = input=>{
  const given = input.split('\n');
  const given_s = given[1];

  const target = given_s[Number(given[2])-1];
  let rtn = "";
  for(let i=0; i<Number(given[0]); i++) rtn += (given_s[i]===target) ? given_s[i]:'*';
  console.log(rtn);
};

Main(require("fs").readFileSync("/dev/stdin", "utf8"));


import * as fs from "fs";
const input = fs.readFileSync("/dev/stdin", "utf8").split("\n");

const [n, s, k] = input;
const char = s[Number(k) - 1];
let result = "";
for (const charS of s) {
    if (charS !== char) {
        result = result + "*";
    } else {
        result = result + char;
    }
}
console.log(result);


function main(input) {
  let [N, S, K] = input.split("\n");
  [N,K] = [N,K].map(v => parseInt(v));
  console.log(S.replace(new RegExp(`[^${S[K-1]}]`, "g"), "*"));
}
main(require("fs").readFileSync("/dev/stdin", "utf8").trim());


import * as fs from "fs";

const input = (fs.readFileSync("/dev/stdin", "utf8") as string).split("\n");
const [n] = input[0].split(" ").map((x: number): number => +x);
const [s] = input[1].split(" ").map((x: string): string => x);
const [k] = input[2].split(" ").map((x: number): number => +x);

const v = s[k-1];
const out = Array(n).fill().reduce((acc, current, i, a)=>{
  if(i === 0){
    return acc
  }
  if(i === k-1){
    return acc+v
  }
  return acc+'*'
}, '*');

console.log(out)


const Main = input=>{
  const given = input.split('\n');
  const given_s = given[1];

  const target = given_s[Number(given[2])];
  let rtn = "";
  for(let i=0; i<Number(given[0]); i++) rtn += (given_s[i]===target) ? given_s[i]:'*';
  console.log(rtn);
};

Main(require("fs").readFileSync("/dev/stdin", "utf8"));


const fs = require('fs')
const stdin = fs.readFileSync('/dev/stdin', 'utf8')

let [n, s, k] = stdin.split('\n')

const i = Number(k) - 1

const repStr = s[i]

const filtered = s.split(repStr).filter(e=>e)

filtered.forEach(e => {
  s = s.replace(e, '*')
})

console.log(s)


n = int(input())
print(n // 3)


N=int(input())
print(N//3)


N = int(input())
print(N//3)


#!/usr/bin/env python3

N = int(input())

ret = 0
for i in range(3, N):
    if N % i == 0:
        ret = max(N//i, ret)

print(ret)


h, w, d = map(int, input().split())
arr = [0] * (h * w + 1)

a = [list(map(int, input().split())) for _ in range(h)]

for i in range(h):
    for j in range(w):
        s = a[i][j]
        arr[s] = (i, j)

q = int(input())
lr = [list(map(int, input().split())) for _ in range(q)]

cnt = h * w
result = [[0] for _ in range(d)]
for i in range(d):
    l = i
    score = 0
    while l + d <= cnt:
        if l == 0:
            result[i].append(score)
            l += d
            continue
        (ux, uy) = arr[l]
        (vx, vy) = arr[l + d]
        score += (abs(vx - ux) + abs(vy - uy))
        result[i].append(score)
        l += d

for l, r in lr:
    ans = result[l % d]
    print(ans[r // d] - ans[l // d])


N = int(input())
print(N*(N+1)/2)


import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

public class Main{
	public static void main(String[] args)throws Exception {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	    String dataDim = br.readLine();
	    StringTokenizer st = new StringTokenizer(dataDim);
	    StringBuilder sb = new StringBuilder();
	    int N = Integer.parseInt(st.nextToken());
	    System.out.println(N/3);
	}
}


import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {
    BufferedReader rd;

    Main() throws IOException {
        rd = new BufferedReader(new InputStreamReader(System.in));
        compute();
    }

    private void compute() throws IOException {
        int n = pint();
        out(n/3);
    }

    private int pint() throws IOException {
        return pint(rd.readLine());
    }

    private int pint(String s) {
        return Integer.parseInt(s);
    }

    private static void out(Object x) {
        System.out.println(x);
    }

    public static void main(String[] args) throws IOException {
        new Main();
    }
}


import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {
    public static void main(String args[]) throws IOException{
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        int n = Integer.parseInt(br.readLine());
        if(n % 3 == 0){
            System.out.println(n/3);
        }
        else{
            System.out.println(n/3);
        }
    }
}


import java.util.*;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		int count = 0;
		int n = N;
		for(int i = 0; i < N;i++) {
			if(n > 3) {
				n = n-3;
				count++;
			}else {
				break;
			}
		}
		System.out.println(count);
	}
}


import java.util.Scanner;
public class A4 {
	public static void main(String[] args) {
		Scanner sc = new Scanner (System.in);

		int N = sc.nextInt();

System.out.println(N/3);

	}
}


import java.util.Arrays;
import java.util.Scanner;

public class Main {

	static Scanner scanner;

	public static void main(String[] args) {
	    scanner = new Scanner(System.in);

        int N=gi();

        for (int i=0; i<N; i++) {
            String s=gs();
            if(s.equals("Y")) {
            	 System.out.println("Four");
            	 return;
            }
        }

	    System.out.println("Three");

//	    if (isNumber(s1) && isNumber(s2) && s.charAt(a) == '-') {
//	    	System.out.print("Yes");
//	    }else {
//	    	System.out.print("No");
//	    }

	}

	public static long d(long n) {
		String a=String.valueOf(n);
		return (long)a.length();
	}

	// 文字列として入力を取得
	public static String gs() {
		return scanner.next();
	}

	// intとして入力を取得
	public static int gi() {
		return Integer.parseInt(scanner.next());
	}

	// longとして入力を取得
	public static long gl() {
		return Long.parseLong(scanner.next());
	}

	// doubleとして入力を取得
	public static double gd() {
		return Double.parseDouble(scanner.next());
	}
}


#include<cstdio>
#include<cstring>
#include<cmath>
#include<cstdlib>
#include<ctime>
#include<algorithm>
#include<queue>
#include<vector>
#define ll long long
#define max(a,b) (a>b?a:b)
#define min(a,b) (a<b?a:b)
#define inf (1ll<<60)
#define mod 1000000007
#define eps 1e-18
inline ll read()
{
    ll tmp=0; char c=getchar(),f=1;
    for(;c<'0'||'9'<c;c=getchar())if(c=='-')f=-1;
    for(;'0'<=c&&c<='9';c=getchar())tmp=(tmp<<3)+(tmp<<1)+c-'0';
    return tmp*f;
}
using namespace std;
int main()
{
	int n=read();
	printf("%d\n",n/3);
	return 0;
}


#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>

int compare_int(const void *a, const void *b)
{
    return *(int*)a - *(int*)b;
}
/*qsort(array, array_size, sizeof(int), compare_int)*/

void sort_char(char *C, int string_long)
{
	int i;
	int num[string_long];
	for (i = 0; i < string_long; i++) {
		num[i] = (int)C[i];
	}
	qsort(num, string_long, sizeof(int), compare_int);
	for (i  =0; i < string_long; i++) {
		C[i] = (char)num[i];
	}
}
/*sort_char(array, strlen(array))*/

void change_int(int *a, int *b)
{
	int c = *a;
	*a = *b;
	*b = c;
}

void change_char(char *s, char *t)
{
	char u = *s;
	*s = *t;
	*t = u;
}

int diff_abso_value(int a, int b)
{
	if (a >= b)
		return a - b;
	else
		return b - a;
}

int main()
{
	int n;
	scanf("%d", &n);
	printf("%d", n/3);
	return 0;
}


#include <cstdio>

int main(void) {
    int n;
    scanf("%d", &n);
    printf("%d\n", n / 3);
    return 0;
}


#include<oistream>
using namespace std;

int main(){
  int n, d;
  cin>>n;
  d=n/3;

  cout<<d<<endl;

  return 0;
}


test.cpp
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#define _USE_MATH_DEFINES
#define forn(i, n) for(lli i=0; i<n; i++)
#define forn1(i, n) for(lli i=1; i<n; i++)
#define debug(x) cerr << "------" << x << endl;
#define All(x) x.begin(), x.end()
#define elif else if
#define lli long long int
#define _USE_MATH_DEFINES
#define _x first
#define _y second

#define _CRT_SECURE_NO_WARNINGS

//#include <bits/stdc++.h>

#include <stdlib.h>
#include <limits.h>
#include <iomanip>
#include <fstream>
#include <algorithm>
#include <iostream>
#include <math.h>
#include <string>
#include <cmath>
#include <numeric>
#include <map>
#include <unordered_map>
#include <vector>
#include <queue>
#include <set>
#include <unordered_set>
#include <bitset>
#include <stack>
#include <list>
#include <sstream>

#include <random>
#include <typeinfo>

using namespace std;

//Constant vars

const lli MOD = 1000000007, LIM = 4294967295;

//Vars

lli n, m, a, b, c, d, q, k, tr, summ, ans, minx, maxx, li, lj, lk, ri, rj, rk, mid, l1, r1, mid1, res, mass1[10000][10000], mass2[100001], mass[100000], from[1000][1000];

string s, trs, str, ss;

//Structures

set<lli> g, bb, all;
set<vector<lli>> myset, myset1, childs[51][51][51];
vector<vector<lli>> myvec[51][51], toWrite, myvec2;
vector<pair<lli, lli>> mm, mm1;
vector<vector<lli>> mvv;
queue<lli> myq;
map<lli, lli> mymap, mymap1, mymap2;
map<lli, vector<lli>> mymapvec;
multiset<lli> mmset;
unordered_map<string, lli> smap;

int compare(const void * a, const void * b) {

	return -((*(lli*)a) - (*(lli*)b));

};

lli gcd(lli a, lli b) {

	while (b != 0) {

		lli t = b;
		b = a % b;
		a = t;

	}

	return a;

}

lli gcdex(lli a, lli b, lli & x, lli & y) {
	if (a == 0) {
		x = 0; y = 1;
		return b;
	}
	lli x1, y1;
	lli d = gcdex(b%a, a, x1, y1);
	x = y1 - (b / a) * x1;
	y = x1;
	return d;
}

lli NOK(lli n1, lli n2) {

	return n1 * n2 / gcd(n1, n2);

}

lli bin_pow(lli base, lli p) {
	if (p == 1) {
		return base % MOD;
	}
	if (p == 0) {
		return 1;
	}

	if (p % 2 == 0) {
		lli t = bin_pow(base, p / 2) % MOD;
		return t * t % MOD;
	}
	else {
		return bin_pow(base, p - 1) * base % MOD;
	}
}

lli inverse_element(lli x) {
	return bin_pow(x, MOD - 2);
}

lli divide(lli a, lli b) {
	return a * inverse_element(b) % MOD;
}

int main() {

	//freopen("input.txt", "r", stdin);
	//freopen("testlist.txt", "w", stdout);

	ios::sync_with_stdio(0);
	cin.tie();

	cin >> n;
	cout << n / 3;

	return 0;
}
//


#include <stdio.h>

int main(void){
int n;scanf("%d", &n); printf("%d\n", n / 3); return 0;}


#include <stdio.h>
int main(void){

    int n;// Y
    scanf("%d",&n);
    printf("%d",n/3);

return 0;
}


#include<stdio.h>
int main()
{
	int a;
	scanf("%d", &a);
	printf("%d\n",a/3);
	return 0;
}


#include <stdio.h>

int main()
{
	int N;
	scanf("%d", &N);
	if (N % 3 == 1) printf("%d\n", N / 3 - 1);
	else printf("%d\n", N / 3);
	fflush(stdout);
	return 0;
}


int main()
{
	int N, x;
	scanf("%d", &N);

	x = N / 3;
	printf("number of group=%d\n", x);
}


#include<stdio.h>
int main()
{
    int N;
    scanf("%d",&N);
    if(N>2)
    {
        printf("%d",N%3);
    }
    else
    {
      printf("%d",0);
    }
    return 0;
}


'use strict';

const Main = input => {
  const howmany = parseInt(input, 10);
  const amari = howmany % 3;
  const Answer = () => {
    switch (amari) {
      case 1:
        return (howmany - 1) / 3;

      case 2:
        return (howmany - 2) / 3;

      case 0:
        return howmany / 3;

      default:
      return 0;
    }
  };
  console.log(Answer());
};
Main(require('fs').readFileSync('/dev/stdin', 'utf8'));


function Main(input){
input  = Number(input);
ans = Math.floor(input / 3);
console.log(ans);
}

Main(require("fs").readFileSync("/dev/stdin", "utf8"));


'use strict'

const main = input => {
	const args = input.split('\n').map(arg => arg.split(' '))
	const N = parseInt(args[0][0], 10)
	console.log(Math.floor(N / 3))
}

main(require('fs').readFileSync('/dev/stdin', 'utf8'))


function main(input) {
  input=input.trim();
const a = parseInt(input.split(" ")[0], 10);
if(a%3==0){
  console.log(Math.floor(a/3));
}else{
  console.log(Math.floor(a/3)+1);
}
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));


function main(input) {
  input=input.trim();
const a = parseInt(input.split(" ")[0], 10);
if(a%3==0){
  console.log(Math.floor(a));
}else{
  console.log(Math.floor(a)+1);
}
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));


function main(input) {
  input=input.trim();
  const a = parseInt(input.split(" ")[0], 10);
console.log(Math.floor(a));
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));


package main

import "fmt"

func main() {
	var n int
	fmt.Scan(&n)
	fmt.Println(n / 3)
}


package main

import (
	"bufio"
	"bytes"
	"fmt"
	"io"
	"os"
	"strconv"
)

func main() {
	defer Flush()

	N := readi()
	println(N / 3)
}

// -----------------------------------------------------------------------------

// IO helper functions

// Returns next token from input.  It must be initialized by SetInput()
// before the first call.
var nextToken func() ([]byte, error)
var nextLine func() ([]byte, error)

// Holds a buffer for output.  It must be initialized by SetOutput().
// All IO fucntions (read*() and [e]print*()) should write to OutputWriter
// instead of this.
var OutputBuffer *bufio.Writer

// Holds an io.Writer.  It must be initialized by SetOutput()
var OutputWriter io.Writer

// Set IO functions for interactive input/output.
func SetInteractive(w io.Writer, r io.Reader) {
	SetUnbefferedInput(r)
	OutputBuffer = nil
	OutputWriter = w
}

// Setup OutputBuffer and OutputWriter.
func SetOutput(w io.Writer) {
	OutputBuffer = bufio.NewWriter(w)
	OutputWriter = OutputBuffer
}

// Flushes OutputBuffer
func Flush() {
	if OutputBuffer != nil {
		OutputBuffer.Flush()
	}
}

// Returns true if c is a white space
func IsSpace(c byte) bool {
	switch c {
	case '\t', '\n', '\v', '\f', '\r', ' ':
		return true
	}
	return false
}

func IsNewLine(c byte) bool {
	switch c {
	case '\n', '\r':
		return true
	}
	return false
}

// Setup nextToken with input buffer.
func SetInput(r io.Reader) {
	buf := new(bytes.Buffer)
	var b []byte

	var i int
	rest := func() ([]byte, error) {
		for i < len(b) && IsSpace(b[i]) {
			i++
		}
		if i == len(b) {
			return nil, io.ErrUnexpectedEOF
		}
		j := i
		for i < len(b) && !IsSpace(b[i]) {
			i++
		}
		return b[j:i], nil
	}
	initial := func() ([]byte, error) {
		io.Copy(buf, r)
		b = buf.Bytes()
		nextToken = rest
		return rest()
	}
	nextToken = initial

	restLn := func() ([]byte, error) {
		for i < len(b) && IsNewLine(b[i]) {
			i++
		}
		if i == len(b) {
			return nil, io.ErrUnexpectedEOF
		}
		j := i
		for i < len(b) && !IsNewLine(b[i]) {
			i++
		}
		return b[j:i], nil
	}

	initialLn := func() ([]byte, error) {
		io.Copy(buf, r)
		b = buf.Bytes()
		nextLine = restLn
		return restLn()
	}
	nextLine = initialLn
}

// Setup nextToken without input buffer.
func SetUnbefferedInput(r io.Reader) {
	buf := bufio.NewReader(r)
	var b []byte

	var i int
	nextToken = func() ([]byte, error) {
		var err error
		if i == len(b) {
			b, err = buf.ReadBytes('\n')
			if err != nil {
				return nil, err
			}
			i = 0
			j := len(b) - 1
			for 0 <= j && IsSpace(b[j]) {
				j--
			}
			b = b[0 : j+1]
		}
		for i < len(b) && IsSpace(b[i]) {
			i++
		}
		j := i
		for i < len(b) && !IsSpace(b[i]) {
			i++
		}
		if i == j {
			return nil, io.ErrUnexpectedEOF
		}
		return b[j:i], nil
	}
}

// -----------------------------------------------------------------------------

// IO functions

// Reads next token and return it as []byte
func readb() []byte {
	b, err := nextToken()
	if err != nil {
		panic(err)
	}
	return b[:len(b):len(b)]
}

// Reads next token and return it as string
func reads() string {
	return string(readb())
}

// Read next line as []byte.  Trailing '\n' will not be included.
// See also comments on readb()
func readbln() []byte {
	b, err := nextLine()
	if err != nil {
		panic(err)
	}
	return b[:len(b):len(b)]
}

// Read next line as string
func readsln() string {
	return string(readbln())
}

// Reads next token and return it as int64
func readll() int64 {
	i, err := strconv.ParseInt(reads(), 10, 64)
	if err != nil {
		panic(err.Error())
	}
	return i
}

// Reads next token and return it as int
func readi() int {
	return int(readll())
}

// Reads next token and return it as float64
func readf() float64 {
	f, err := strconv.ParseFloat(reads(), 64)
	if err != nil {
		panic(err.Error())
	}
	return f
}

// Write args to OutputWriter with the format f
func printf(f string, args ...interface{}) (int, error) {
	return fmt.Fprintf(OutputWriter, f, args...)
}

// Write args to OutputWriter without format
func println(args ...interface{}) (int, error) {
	return fmt.Fprintln(OutputWriter, args...)
}

// Write args to stderr with the format f
func eprintf(f string, args ...interface{}) (int, error) {
	return fmt.Fprintf(os.Stderr, f, args...)
}

// Write args to stderr without format
func eprintln(args ...interface{}) (int, error) {
	return fmt.Fprintln(os.Stderr, args...)
}

// -----------------------------------------------------------------------------

// Utilities

func sumSlice(a []int) int {
	var res int
	for _, v := range a {
		res += v
	}
	return res
}

func sumSlicell(a []int64) int64 {
	var res int64
	for _, v := range a {
		res += v
	}
	return res
}

func readInts(N int) (int, []int) {
	if N == 0 {
		N = readi()
	}
	a := make([]int, N)
	for i := range a {
		a[i] = readi()
	}
	return N, a
}

func readIntsll(N int) (int, []int64) {
	if N == 0 {
		N = readi()
	}
	a := make([]int64, N)
	for i := range a {
		a[i] = readll()
	}
	return N, a
}

// reverse slice in place
func reverse(a []int) {
	for i, j := 0, len(a)-1; i < j; i, j = i+1, j-1 {
		a[i], a[j] = a[j], a[i]
	}
}

// areverse: allocating reverse
func areverse(a []int) []int {
	b := make([]int, len(a))
	for i := range a {
		b[i] = a[len(a)-i-1]
	}
	return b
}

// -----------------------------------------------------------------------------

// Simple math functions

const (
	// big prime
	INF  = 1000000007
	INF2 = 1000000009
	INF3 = 998244353
)

func min(a, b int) int {
	if a < b {
		return a
	}
	return b
}

func minll(a, b int64) int64 {
	if a < b {
		return a
	}
	return b
}

func minf(a, b float64) float64 {
	if a < b {
		return a
	}
	return b
}

func max(a, b int) int {
	if a < b {
		return b
	}
	return a
}

func maxll(a, b int64) int64 {
	if a < b {
		return b
	}
	return a
}

func maxf(a, b float64) float64 {
	if a < b {
		return b
	}
	return a
}

func abs(a int) int {
	if a < 0 {
		return -a
	}
	return a
}

func absll(a int64) int64 {
	if a < 0 {
		return -a
	}
	return a
}

func absf(a float64) float64 {
	if a < 0 {
		return -a
	}
	return a
}

// egcd(a, b) returns d, x, y:
//   d is gcd(a,b)
//   x, y are  integers that satisfy ax + by = d
func egcd(a, b int) (int, int, int) {
	if b == 0 {
		return a, 1, 0
	}
	d, x, y := egcd(b, a%b)
	return d, y, x - a/b*y
}

func egcdll(a, b int64) (int64, int64, int64) {
	if b == 0 {
		return a, 1, 0
	}
	d, x, y := egcdll(b, a%b)
	return d, y, x - a/b*y
}

func gcd(a, b int) int {
	d, _, _ := egcd(a, b)
	return d
}

func gcdll(a, b int64) int64 {
	d, _, _ := egcdll(a, b)
	return d
}

// set up IO functions
func init() {
	// for non-interactive
	SetInput(os.Stdin)
	SetOutput(os.Stdout)

	// Enable below when interactive.  Its ok to leave above intact.
	// SetInteractive(os.Stdout, os.Stdin)
}


package main

import (
	"fmt"
)

func maint() {
	var n int
	fmt.Scan(&n)

	fmt.Println(n/3)
}


package main

import "fmt"

func main() {
	var n int
	fmt.Scan(&n)
	var shurui []rune
	for i := 0; i < n; i++ {
		var char rune
		fmt.Scan(&char)
		for i,c := range shurui {
			if c == char{
				break
			}
			if i == len(shurui)-1{
				shurui = append(shurui, char)
			}
		}
		if len(shurui) == 3{
			fmt.Println("Three")
		} else if len(shurui) == 4{
			fmt.Println("Four")
		}
	}
}


package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

var sc = bufio.NewScanner(os.Stdin)

func nextInt() int {
	sc.Scan()
	i, e := strconv.Atoi(sc.Text())
	if e != nil {
		panic(e)
	}
	return i
}

func nextLine() string {
	sc.Scan()
	return sc.Text()
}

func main() {
	// sc.Split(bufio.ScanWords)
	var n int
	fmt.Scan(&n)
	m := map[string]int{}
	var s string
	for i := 0; i < n; i++ {
		fmt.Scan(&s)
		m[string(s[0])]++
	}

	march := "MARCH"

	ans := 0
	for i := 0; i < n; i++ {
		for j := i + 1; j < n; j++ {
			for k := j + 1; k < n; k++ {
				ans += m[string(march[i])] * m[string(march[j])] * m[string(march[k])]
			}
		}
	}

	fmt.Println(ans)
}


puts gets.to_i / 3


p gets.to_i/3


puts gets.chomp.to_i/3


p gets.to_i%3


puts get.chomp.to_i/2


# ある学校には、N 人の生徒がいます。
# 生徒たちをいくつかのグループに分け、グループごとにあるテーマについて話し合ってもらうこととなりました。
# あなたは、2 人以下のグループだと効果的な話し合いが出来ないと考えており、
# なるだけ多くのグループを 3 人以上にしたいです。
# 生徒たちを上手く分けて、3 人以上のグループの数を最大化してください。

n = gets.to_i
group_count = n / 3
puts n % 3 == 0 ? group_count : group_count - 1


use std::io::*;
use std::str::FromStr;

pub fn read<T: FromStr>() -> T {
    let stdin = stdin();
    let stdin = stdin.lock();
    let token: String = stdin
        .bytes()
        .map(|c| c.expect("failed to read char") as char)
        .skip_while(|c| c.is_whitespace())
        .take_while(|c| !c.is_whitespace())
        .collect();
    token.parse().ok().expect("failed to parse token")
}

fn main() {
    let n: usize = read();
    println!("{}", n / 3);
}


use std::io;

fn procon_read<T: std::str::FromStr>() ->  Vec<T> {
	let mut buf = String::new();
	io::stdin().read_line(&mut buf).expect("");
	let iter = buf.split_whitespace();
	let mut v: Vec<T> = Vec::new();
	for i in iter {
		v.push(i.parse().ok().unwrap());
	}
	v
}

fn main() {
	let v:Vec<i32> = procon_read();
	let n = v[0];
	println!("{}", n/3);
}


// Template from https://techracho.bpsinc.jp/jhonda/2019_08_05/78537

// input macro for competive-programming from https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8
#[allow(unused_macros)]
macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
        let mut iter = $s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
}

#[allow(unused_macros)]
macro_rules! input_inner {
    ($iter:expr) => {};
    ($iter:expr, ) => {};

    ($iter:expr, $var:ident : $t:tt $($r:tt)*) => {
        let $var = read_value!($iter, $t);
        input_inner!{$iter $($r)*}
    };

    ($iter:expr, mut $var:ident : $t:tt $($r:tt)*) => {
        let mut $var = read_value!($iter, $t);
        input_inner!{$iter $($r)*}
    };
}

#[allow(unused_macros)]
macro_rules! read_value {
    ($iter:expr, ( $($t:tt),* )) => {
        ( $(read_value!($iter, $t)),* )
    };

    ($iter:expr, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($iter, $t)).collect::<Vec<_>>()
    };

    ($next:expr, [ $t:tt ]) => {
        {
            let len = read_value!($next, usize);
            (0..len).map(|_| read_value!($next, $t)).collect::<Vec<_>>()
        }
    };

    ($iter:expr, chars) => {
        read_value!($iter, String).chars().collect::<Vec<char>>()
    };

    ($iter:expr, bytes) => {
        read_value!($iter, String).into_bytes()
    };

    ($iter:expr, $t:ty) => {
        $iter.next().unwrap().parse::<$t>().expect("Parse error")
    };
}

fn main() {
    use std::io::Read;
    let mut s = String::new();
    std::io::stdin().read_to_string(&mut s).unwrap();

    println!("{}", solve(&s));
}

macro_rules! test {
    ($($input:expr => $output:expr),* $(,)*) => {
        #[test]
        fn solve_test() {
            $(
                assert_eq!(solve($input), $output);
            )*
        }
    };
}

test! {
r#"2018 218"# => "Yes",
r#"2763 0"# => "No",
//
}

fn solve(src: &str) -> String {
    input! {
        source = src,
        n: i64,
    }

    (n / 3) .to_string()
}


import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		try (Scanner scanner = new Scanner(System.in)) {
			int n = scanner.nextInt();
			System.out.println(n / 3);
		}
	}
}


fn main() {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).unwrap();
    let n: i32 = s.parse().unwrap();
    println!("{}", n/3);
}


fn main() {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).unwrap();
    let n: usize = s.parse().unwrap();
    println!("{}", n/3);
}


import Glibc
extension String: CollectionType {}

//var inp = readLine()!.split(" ").map { Int($0)! }
var n = Int(readLine()!)!
print(n / 3)


#include <algorithm>
#include <cmath>
#include <cstdio>
#include <cstring>
#include <deque>
#include <iostream>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <utility>
#include <vector>

#define CK(N, A, B) (A <= N && N < B)
#define REP(i, a, b) for (int i = a; i < b; i++)
#define RREP(i, a, b) for (int i = (b - 1); a <= i; i--)
#define F first
#define S second
#define ll long long

const int INF = 1e9;
const long long LLINF = 1e18;

using namespace std;

int dy[] = {0,1,0,-1};
int dx[] = {1,0,-1,0};
int dy8[] = {0,1,1,1,0,-1,-1,-1};
int dx8[] = {1,1,0,-1,-1,-1,0,1};

/*==================================================*/
/*variable*/
int N;
/*==================================================*/
/*function*/

/*==================================================*/

int main() {
    cin>>N;
    cout<<N/3<<endl;
    return 0;
}


const input=require('fs').readFileSync('/dev/stdin', 'utf8').split(/[\s]/);const nin=()=>{const r = input[0];input.shift();return Number(r)};const nrin=(n)=>{const a:number[]=[];rep(n,()=>a.push(nin()));return a};const sin=()=>{const r = input[0];input.shift();return String(r)};const out=(...a)=>{console.log(...a)};const floor=(a)=>{return Math.floor(a)};const abs=(a)=>{return Math.abs(a)};const min=(...a)=>{return Math.min(...a)};const max=(...a)=>{return Math.max(...a)};const rep=(n, callback)=>{for(let i = 0;i < n; i++){callback()}};const strrep=(s, i, v)=>{return s.slice(0, i)+v+s.slice(i+1);};const permutation=({result=[],pre=[],post,n=post.length})=>{if(n>0){post.forEach((_,i)=>{const rest=[...post];const elem=rest.splice(i, 1);permutation({result, pre: [...pre,...elem],post:rest,n:n-1})})}else{result.push(pre)}return result};const sw=(s,a:any[],op:'=='|'>='|'>'|'<='|'<'='==')=>{for(let i=0;i<a.length;i+=2){if(op==='=='){if(s==a[i])return a[i+1]}else if(op==='>='){if(s>=a[i])return a[i+1]}else if(op==='<='){if(s<=a[i])return a[i+1]}else if(op==='>'){if(s>a[i])return a[i+1]}else if(op==='<'){if(s<a[i])return a[i+1]}}return a[a.length-1];};const or=(a,...b)=>{for(let i=0;i<b.length;i++)if(a==b[i])return true;return false};const maxindex=(...a)=>{return a.indexOf(Math.max.apply(null,a))};const asc=(ar:number[])=>{return ar.sort((a,b)=>{return a-b})};const desc=(ar:number[])=>{return ar.sort((a,b)=>{return b-a})};const ceil=a=>{return Math.ceil(a)};const srin=s=>{const a:string[]=[];rep(s,()=>a.push(sin()));return a};let ssinteger=-1;const ssin=()=>{ssinteger++;return input[0][ssinteger]};
const main = ()=>{
  out(floor(nin()/3))
}
main()


import * as fs from 'fs';

namespace AtCoder.abc001 {

    export class Program {

        constructor(private readonly args: string[][]) {
        }

        /**
         * in
         *
         * out
         *
         */
        main(this: Program): void {
            const n: number = parseInt(this.args[0][0], 10);

            console.log(Math.floor(n / 3));

        }
    }
}

const args: string[][] = fs.readFileSync('/dev/stdin', 'utf8').trim().split('\n').map(r => r.split(' '));
const prg: AtCoder.abc001.Program = new AtCoder.abc001.Program(args);
prg.main();


const main = (input) => {
  input = input.split(' ');
  const N = parseInt(input[0], 10);

  console.log(Math.floor(N/3));

}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));


const main = (input) => {
  input = input.split(' ');
  const N = parseInt(input[0], 10);

  console.log(N%3);

}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));


const main = (input) => {
  input = input.split(' ');
  const N = parseInt(input[0], 10);

  console.log(N/3);

}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));


declare function require(x: string): any;

    const main = (input: string[][]) => {
        const s: string[] = input[1];
        if (s.every((c) => c != 'Y')) {
            console.log('Three');
        } else {
            console.log('Four');
        }
    };

const whole_input: string = require('fs').readFileSync('/dev/stdin', 'utf8');
main(whole_input.split('\n').map((s: string) => s.split(' ')));zx


n,k = map(int,input().split())
a = []
for i in range(1,n+1,2):
    a.append(i)

if len(a) >= k:
    print('YES')
else:
    print('NO')


N, K = list(map(int, input().split()))

if (N+1) // 2 >= K:
    print('YES')
else:
    print('NO')


N, K= map(int, input().split())

if N%2==0:
    max_num=N//2
    if max_num>=K:
        print("YES")
    else:
        print("NO")
else:
    max_num=N//2+1
    if max_num>=K:
        print("YES")
    else:
        print("NO")


k, a, b = map(int, input().split())

if a + 1 >= b:
  print(1 + k)

else:
  if k < a + 1:
    print(1 + k)
  else:

    a1 = b #a+1回
    if (k - (a + 1)) % 2 == 0:
      a2 = ((k - (a + 1)) // 2) * (b - a)
    else:
      a2 = ((k - (a + 1) - 1) // 2) * (b - a) + 1
    print(a1 + a2)


N, K = map(int, input().split())
if N + 1 >= 2 * K:
  print("Yes")
else:
  print("No")


n,k = map(int,input().split())
print("YES" if (n+1)%2<=k else "NO")


import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Arrays;

public class Main {

	public static void main(String[] args) throws Exception {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		int K = sc.nextInt();

		if (N >= (K - 1) * 2 + 1) {
			System.out.println("YES");
		} else {
			System.out.println("NO");
		}

	}

	private static boolean isDebug = System.getProperty("sun.desktop") != null;

	private static void debug(Object... o) {
		if (isDebug) {
			System.err.println(Arrays.deepToString(o));
		}
	}

	public static class Scanner {
		private BufferedInputStream inputStream;
		private StringBuilder buffer = new StringBuilder();

		public Scanner(InputStream in) {
			inputStream = new BufferedInputStream(in);
		}

		public int nextInt() throws IOException {
			int num = 0;
			int sign = 1;

			int read = skip();
			if (read == '-') {
				sign = -1;
				read = inputStream.read();
			}

			do {
				num = num * 10 + sign * (read - 0x30);
			} while ((read = inputStream.read()) > 0x20);

			return num;
		}

		public void fill(int[] a) throws IOException {
			for (int i = 0; i < a.length; i++) {
				a[i] = nextInt();
			}
		}

		public void fill(int[] a, int[] b) throws IOException {
			if (a.length != b.length) {
				throw new IllegalArgumentException();
			}

			for (int i = 0; i < a.length; i++) {
				a[i] = nextInt();
				b[i] = nextInt();
			}
		}

		public long nextLong() throws IOException {
			long num = 0;
			int sign = 1;

			int read = skip();
			if (read == '-') {
				sign = -1;
				read = inputStream.read();
			}

			do {
				num = num * 10 + sign * (read - 0x30);
			} while ((read = inputStream.read()) > 0x20);

			return num;
		}

		public void fill(long[] a) throws IOException {
			for (int i = 0; i < a.length; i++) {
				a[i] = nextLong();
			}
		}

		public void fill(long[] a, long[] b) throws IOException {
			if (a.length != b.length) {
				throw new IllegalArgumentException();
			}

			for (int i = 0; i < a.length; i++) {
				a[i] = nextLong();
				b[i] = nextLong();
			}
		}

		public long[] nextLong(int n) throws IOException {
			long[] array = new long[n];
			for (int i = 0; i < n; i++) {
				array[i] = nextLong();
			}

			return array;
		}

		public String next() throws IOException {
			int read = skip();
			do {
				buffer.append((char) read);
			} while ((read = inputStream.read()) > 0x20);

			String text = buffer.toString();
			buffer.delete(0, buffer.length());

			return text;
		}

		private int skip() throws IOException {
			int read;
			while ((read = inputStream.read()) <= 0x20)
				;

			return read;
		}
	}
}


import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.charset.StandardCharsets;

public class Main {
	public static void main(String[] args) throws IOException {
		String[] inputS = new String[2];
		Integer n, k = 0;
		String ans = "NO";
		try (BufferedReader br = new BufferedReader(new InputStreamReader(System.in, StandardCharsets.UTF_8))) {
			inputS = br.readLine().split(" ");
			n = Integer.valueOf(inputS[0]);
			k = Integer.valueOf(inputS[1]);
		}
		if (n % 2 != 0) {
			n += 1;
		}
		if((n / 2) >= k) {
			ans = "YES";
		}
		System.out.println(ans);
	}
}


import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.InputMismatchException;

public class Main {
	static InputStream is;
	static PrintWriter out;
	static String INPUT = "";

	static void solve()
	{
		int n = ni(), K = ni();
		out.println(1+(K-1)*2 <= n ? "YES" : "NO");
	}

	public static void main(String[] args) throws Exception
	{
		long S = System.currentTimeMillis();
		is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes());
		out = new PrintWriter(System.out);

		solve();
		out.flush();
		long G = System.currentTimeMillis();
		tr(G-S+"ms");
	}

	private static boolean eof()
	{
		if(lenbuf == -1)return true;
		int lptr = ptrbuf;
		while(lptr < lenbuf)if(!isSpaceChar(inbuf[lptr++]))return false;

		try {
			is.mark(1000);
			while(true){
				int b = is.read();
				if(b == -1){
					is.reset();
					return true;
				}else if(!isSpaceChar(b)){
					is.reset();
					return false;
				}
			}
		} catch (IOException e) {
			return true;
		}
	}

	private static byte[] inbuf = new byte[1024];
	static int lenbuf = 0, ptrbuf = 0;

	private static int readByte()
	{
		if(lenbuf == -1)throw new InputMismatchException();
		if(ptrbuf >= lenbuf){
			ptrbuf = 0;
			try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); }
			if(lenbuf <= 0)return -1;
		}
		return inbuf[ptrbuf++];
	}

	private static boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); }
//	private static boolean isSpaceChar(int c) { return !(c >= 32 && c <= 126); }
	private static int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; }

	private static double nd() { return Double.parseDouble(ns()); }
	private static char nc() { return (char)skip(); }

	private static String ns()
	{
		int b = skip();
		StringBuilder sb = new StringBuilder();
		while(!(isSpaceChar(b))){
			sb.appendCodePoint(b);
			b = readByte();
		}
		return sb.toString();
	}

	private static char[] ns(int n)
	{
		char[] buf = new char[n];
		int b = skip(), p = 0;
		while(p < n && !(isSpaceChar(b))){
			buf[p++] = (char)b;
			b = readByte();
		}
		return n == p ? buf : Arrays.copyOf(buf, p);
	}

	private static char[][] nm(int n, int m)
	{
		char[][] map = new char[n][];
		for(int i = 0;i < n;i++)map[i] = ns(m);
		return map;
	}

	private static int[] na(int n)
	{
		int[] a = new int[n];
		for(int i = 0;i < n;i++)a[i] = ni();
		return a;
	}

	private static int ni()
	{
		int num = 0, b;
		boolean minus = false;
		while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
		if(b == '-'){
			minus = true;
			b = readByte();
		}

		while(true){
			if(b >= '0' && b <= '9'){
				num = num * 10 + (b - '0');
			}else{
				return minus ? -num : num;
			}
			b = readByte();
		}
	}

	private static long nl()
	{
		long num = 0;
		int b;
		boolean minus = false;
		while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
		if(b == '-'){
			minus = true;
			b = readByte();
		}

		while(true){
			if(b >= '0' && b <= '9'){
				num = num * 10 + (b - '0');
			}else{
				return minus ? -num : num;
			}
			b = readByte();
		}
	}

	private static void tr(Object... o) { if(INPUT.length() != 0)System.out.println(Arrays.deepToString(o)); }
}


import java.util.Scanner;

public class Main {
	public static void main(String[]args) {
		try(Scanner scan = new Scanner(System.in)){

			long K = scan.nextLong();
			long A = scan.nextLong();
			long B = scan.nextLong();

			if(B-A>2) {
				if(1+K<A+2) {
					System.out.println(1+K);
				}else {

					K=K-(A-1);

					long s = K/2;
					long r = K%2;

					long goukei =1+(A-1)+s*(B-A)+r;

					System.out.println(goukei);

				}

			}else{
				System.out.println(1+K);
			}

		}

	}

}


import java.util.Scanner;
public class Main {
    public static void main(String[] args){

    Scanner sc = new Scanner(System.in);
    int n  = sc.nextInt();
	int k  = sc.nextInt();

    if(k*2-1 <= n) {
    	System.out.println("Yes");
    }else {
    	System.out.println("No");
    }
}
}


import java.util.Scanner;

public class Main {

	static Scanner scanner;
	public static void main(String[] args) {
	    scanner = new Scanner(System.in);

	    int n=gi();
	    int k=gi();

	    //System.out.print(a-b+1);
	    if (Math.floorDiv(n+1, 2) <=k) {
	    	System.out.print("YES");
	    }else {
	    	System.out.print("NO");
	    }

	}

	public static long d(long n) {
		String a=String.valueOf(n);
		return (long)a.length();
	}

	// 文字列として入力を取得
	public static String gs() {
		return scanner.next();
	}

	// intとして入力を取得
	public static int gi() {
		return Integer.parseInt(scanner.next());
	}

	// longとして入力を取得
	public static long gl() {
		return Long.parseLong(scanner.next());
	}

	// doubleとして入力を取得
	public static double gd() {
		return Double.parseDouble(scanner.next());
	}
}


#include <bits/stdc++.h>
using namespace std;

int main() {
  int N, K;
  cin >> N >> K;

  if(N>=(K*2-1)){
  	cout << "YES" << endl;
  }else{
  	cout << "NO" << endl;
  }
  return 0;
}


#include <bits/stdc++.h>  // g++ -std=c++14 -o a a.cpp

using namespace std;

typedef pair<int, int> P;
typedef long long ll;

#define rep(i, n) for(int i = 0; i < (n); i++)
#define repto(i, n) for(int i = 0; i <= (n); i++)
#define all(c) (c).begin(), (c).end()
#define uniq(c) c.erase(unique(all(c)), (c).end())
#define _1 first
#define _2 second
#define pb push_back
#define INF 1145141919
#define MOD 1000000007
#define DEBUG(x) cout << #x << ": " << x << endl;

int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};

__attribute__((constructor)) void initial() {
    cin.tie(0);
    ios::sync_with_stdio(false);
}

int main() {
    int N, K;
    cin >> N >> K;
    int M = N / 2 + N % 2;
    cout << ((M >= K) ? "YES" : "NO") << endl;
}


#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
#define rep(i, n) for(ll i = 0;i < n;i++)
template<class T, class U> void cmax(T& a, U b) { if (a<b) a = b; }
template<class T, class U> void cmin(T& a, U b) { if (a>b) a = b; }

int main() {
  cin.tie(0); ios::sync_with_stdio(false);

  int n, k;
  cin >> n >> k;
  if (k <= (n+1)/2) {
    cout << "YES" << endl;
  } else {
    cout << "NO" << endl;
  }
}


#include <iostream>
using namespace std;
int main() {
    int N, K; cin>>N>>K;
    N-K >= K-1 ? cout<<"Yes"<<endl : cout<<"No"<<endl;
    return 0;
}


#include <bits/stdc++.h>
typedef long long ll;
using namespace std;

int main() {
	vector<vector<int>> g(4);
	for (int i = 0; i < 3; i++) {
		int u, v;
		cin >> u >> v;
		u--, v--;
		g[u].push_back(v);
		g[v].push_back(u);
	}

	int odds = 0;
	for (int i = 0; i < 4; i++) {
		if (g[i].empty()) {
			cout << "NO\n";
			return 0;
		}
		if (g[i].size() % 2 == 1) {
			odds++;
		}
	}

	cout << (odds == 0 || odds == 2 ? "YES" : "NO") << '\n';

	return 0;
}


#include<bits/stdc++.h>
using namespace std;
#define int long long
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define rep1(i, n) for (int i = 1; i <= (int)(n); i++)
#define rev(i, n) for(int i = (int)(n - 1); i >= 0; i--)
#define rev1(i, n) for(int i = (int)(n); i > 0; i--)
#define pb push_back
#define ts to_string
#define all(v) (v).begin(), (v).end()
#define vi vector<int>
#define vvi vector<vector<int>>
#define vc vector<char>
#define vvc vector<vector<char>>
#define vs vector <string>
#define vvs vector <vector<string>>
#define pq  priority_queue<int>
using ll = long long;
/* ----------------よく使う数字や配列----------------- */
int dx[] = { 1,0,-1,0 };
int dy[] = { 0,1,0,-1 };
const int INF = 2000000000;
const int MINF=-2000000000;
constexpr ll mod = 1e9 + 7;
constexpr long double pi = 3.141592653589793238462643383279;
/* ----------------------end----------------------- */
/*---------------------template----------------------*/
/*----------------------end--------------------------*/
/* --------------------ライブラリ-------------------- */
ll fact(int i) {       //階乗
    if (i == 0) return 1;
    return (fact(i - 1)) * i % mod;
}
ll gcd(ll a, ll b) {        //最大公約数
    if (b == 0) return a;
    return gcd(b, a % b);
}
ll lcm(ll a, ll b) {      //最小公倍数
    return a * b / gcd(a, b);
}
bool isprime(ll a)//素数判定、primeならtrue,違うならfalse
{
    if (a < 2) return false;
    else if (a == 2) return true;
    else if (a % 2 == 0) return false;
    double m = sqrt(a);
    for (int i = 3; i <= m; i += 2)
    {
        if (a % i == 0)
        {
            return false;
        }
    }
    // 素数である
    return true;
}
ll ketasum(ll n) {    //各桁の和
    ll sum = 0;
    while (n != 0) {
        sum += n % 10;
        n /= 10;
    }
    return sum;
}
/* ----------------------end----------------------- */
signed main(){
  int N,K;cin>>N>>K;
  N>K?puts("YES"):puts("NO");
}


#include <stdio.h>

int main() {
	int N, K;
	scanf("%d %d", &N, &K);
	if (K * 2 - 1 <= N)
		printf("YES\n");
	else
		printf("NO\n");
	return 0;
}


int n, k;
int main(){
  scanf("%d%d", &n, &k);
  if(k*2-1<= n){
    puts("YES");
  }else{
    puts("NO");
  }
}


#include <stdio.h>

int main()
{
	int n, k;
	int count = 0;

	scanf("%d%d", &n, &k);

	for (int i = 1; i <= n; i += 2) {
		count++;
	}

	if (count >= k)
		printf("YES\n");
	else
		printf("NO\n");

	return 0;
}


#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>

#define i_cin(X) scanf("%d", &X)
#define i_cin2(X,Y) scanf("%d %d",&X,&Y)
#define i_cin3(X,Y,Z) scanf("%d %d %d",&X,&Y,&Z)
#define l_cin(X) scanf("%ld",&X)
#define l_cin2(X,Y) scanf("%ld %ld",&X,&Y)
#define s_cin(X) scanf("%s",&X)

#define  i_cout(X) printf("%d\n",X)
#define  f_cout(X) printf("%g\n",X)
#define  i_cout2(X,Y) printf("%d %d\n",X,Y)
#define  l_cout(X) printf("%ld\n",X)
#define  s_cout(X) printf("%s\n",X)
#define  ll_cout(X) printf("%lld\n",X)

typedef long long int lli;
#define rept(x, s, n) for (int x = s; x < n; x++)

#define Yes_RTN s_cout("Yes");return 0
#define No_RTN  s_cout("No");return 0
#define YES_RTN s_cout("YES");return 0
#define NO_RTN  s_cout("NO");return 0

int i_cins(int n, int* A);
int l_cins2(int n, long* A,long* B);
int s_dsort(const void* a, const void* b);
int s_asort(const void* a, const void* b);

int main(void) {

	int    N,K,count;

	i_cin2(N,K);
	if (K == 1) { NO_RTN; }
	if ((N / 3) + 1 >= K) { YES_RTN; }
	NO_RTN;
	}

//降順
int s_dsort(const void* a, const void* b) {
	return(*(int*)b - *(int*)a);
}
int s_asort(const void* a, const void* b) {
	return(*(int*)a -*(int*)b);
}
//
int l_cins2(int n, long* a, long* b) {
	int i;
	rept(i, 0, n) {
		l_cin2(*(a + i), *(b + i));
	}
	return 0;
}
int i_cins(int n, int* a) {
	int i;
	rept(i, 0, n) {
		i_cin(*(a + i));
	}

	return 0;
}


#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>

#define i_cin(X) scanf("%d", &X)
#define i_cin2(X,Y) scanf("%d %d",&X,&Y)
#define i_cin3(X,Y,Z) scanf("%d %d %d",&X,&Y,&Z)
#define l_cin(X) scanf("%ld",&X)
#define l_cin2(X,Y) scanf("%ld %ld",&X,&Y)
#define s_cin(X) scanf("%s",&X)

#define  i_cout(X) printf("%d\n",X)
#define  f_cout(X) printf("%g\n",X)
#define  i_cout2(X,Y) printf("%d %d\n",X,Y)
#define  l_cout(X) printf("%ld\n",X)
#define  s_cout(X) printf("%s\n",X)
#define  ll_cout(X) printf("%lld\n",X)

typedef long long int lli;
#define rept(x, s, n) for (int x = s; x < n; x++)

#define Yes_RTN s_cout("Yes");return 0
#define No_RTN  s_cout("No");return 0
#define YES_RTN s_cout("YES");return 0
#define NO_RTN  s_cout("NO");return 0

int i_cins(int n, int* A);
int l_cins2(int n, long* A,long* B);
int s_dsort(const void* a, const void* b);
int s_asort(const void* a, const void* b);

int main(void) {

	int    N,K,count;

	i_cin2(N,K);
	if ((N / 3) + 1 >= K) { YES_RTN; }
	NO_RTN;
	}

//降順
int s_dsort(const void* a, const void* b) {
	return(*(int*)b - *(int*)a);
}
int s_asort(const void* a, const void* b) {
	return(*(int*)a -*(int*)b);
}
//
int l_cins2(int n, long* a, long* b) {
	int i;
	rept(i, 0, n) {
		l_cin2(*(a + i), *(b + i));
	}
	return 0;
}
int i_cins(int n, int* a) {
	int i;
	rept(i, 0, n) {
		i_cin(*(a + i));
	}
	return 0;
}


#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>

#define i_cin(X) scanf("%d", &X)
#define i_cin2(X,Y) scanf("%d %d",&X,&Y)
#define i_cin3(X,Y,Z) scanf("%d %d %d",&X,&Y,&Z)
#define l_cin(X) scanf("%ld",&X)
#define l_cin2(X,Y) scanf("%ld %ld",&X,&Y)
#define s_cin(X) scanf("%s",&X)

#define  i_cout(X) printf("%d\n",X)
#define  f_cout(X) printf("%g\n",X)
#define  i_cout2(X,Y) printf("%d %d\n",X,Y)
#define  l_cout(X) printf("%ld\n",X)
#define  s_cout(X) printf("%s\n",X)
#define  ll_cout(X) printf("%lld\n",X)

typedef long long int lli;
#define rept(x, s, n) for (int x = s; x < n; x++)

#define YES_RTN s_cout("Yes");return 0
#define NO_RTN  s_cout("No");return 0

int i_cins(int n, int* A);
int l_cins2(int n, long* A,long* B);
int s_dsort(const void* a, const void* b);
int s_asort(const void* a, const void* b);

int main(void) {

	int    N,K,count;

	i_cin2(N,K);
	if ((N / 3) + 1 >= K) { YES_RTN; }
	NO_RTN;
	}

//降順
int s_dsort(const void* a, const void* b) {
	return(*(int*)b - *(int*)a);
}
int s_asort(const void* a, const void* b) {
	return(*(int*)a -*(int*)b);
}
//
int l_cins2(int n, long* a, long* b) {
	int i;
	rept(i, 0, n) {
		l_cin2(*(a + i), *(b + i));
	}
	return 0;
}
int i_cins(int n, int* a) {
	int i;
	rept(i, 0, n) {
		i_cin(*(a + i));
	}
	return 0;
}


function Main(input) {
	input = input.split(" ").map(Number);
	console.log((input[0]+1)/2>=input[1]?"YES":"NO")

}Main(require("fs").readFileSync("/dev/stdin", "utf8").trim());


function Main(input) {
  input = input.split("\n");
  var N = parseInt(input[0].split(" ")[0]);
  var K = parseInt(input[0].split(" ")[1]);
  var ans ="NO";
  if(Math.ceil(N/2)>=K){
    ans="YES";
  }

  console.log('%s', ans);
}

// "実行する"ボタンを押した時に実行される関数 (デバッグ用)
function debug(){
  var input = document.getElementById("input").value;
  Main(input);
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));


'use strict'

const main = (INPUT) => {
  const N = Number(INPUT.split('\n')[0].split(' ')[0])
  const K = Number(INPUT.split('\n')[0].split(' ')[1])

  if ((N + 1) / 2 >= K) {
    console.log('YES')
  } else {
    console.log('NO')
  }
}

main(require('fs').readFileSync('/dev/stdin', 'utf8'))


var input = require("fs").readFileSync("/dev/stdin", "utf8").trim().split("\n");
var obj = {
  "list" : input, "index" : 0, "max" : input.length,
  "hasNext" : function(){return (this.index < this.max);},
  "next" : function(){
    if(!this.hasNext()){throw "NoSuchElementException:次に要素は無いよ";}
    var returnObj = this.list[this.index];
    this.index++;
    return returnObj;
  }
}
Main();
function next(){return obj.next();}
function nextInt(){return myconv(next(),1);}
function nextStrArray(){return myconv(next(),2);}//半角スペース分割
function nextIntArray(){return myconv(next(),4);}//半角スペース + 数値化
function nextCharArray(){return myconv(next(),6);}//1文字分割
function hasNext(){return obj.hasNext();}
function myout(t){console.log(t);}//標準出力
function myerr(t){console.error(t);}//標準エラー出力
//[no]要素の扱い。数値型
//不明値、異常時:引数そのまま返す　1:数値へ変換
//2:半角SPで分割 4:半角SPで分割し、数値配列へ
//6:1文字で分割  7:1文字で分割し、数値配列へ
//8:半角SPで結合 9:改行で結合 0:文字なしで結合
function myconv(i,no){try{switch(no){case 1:return parseInt(i);case 2:return i.split(" ");case 4:return i.split(" ").map((a)=>Number(a));case 6:return i.split("");case 7:return i.split("").map((a)=>Number(a));case 8:return i.join(" ");case 9:return i.join("\n");case 0:return i.join("");default:return i;}}catch(e){return i;}}
function Main(){
  var one = nextIntArray();
  var N = one[0];
  var K = one[1];
  var tmp = Math.ceil(N / 2);
  if(tmp >= K){
     myout("Yes");
  }else{
     myout("No");
  }
}


var input = require("fs").readFileSync("/dev/stdin", "utf8").trim().split("\n");
var obj = {
  "list" : input, "index" : 0, "max" : input.length,
  "hasNext" : function(){return (this.index < this.max);},
  "next" : function(){
    if(!this.hasNext()){throw "NoSuchElementException:次に要素は無いよ";}
    var returnObj = this.list[this.index];
    this.index++;
    return returnObj;
  }
}
Main();
function next(){return obj.next();}
function nextInt(){return myconv(next(),1);}
function nextStrArray(){return myconv(next(),2);}//半角スペース分割
function nextIntArray(){return myconv(next(),4);}//半角スペース + 数値化
function nextCharArray(){return myconv(next(),6);}//1文字分割
function hasNext(){return obj.hasNext();}
function myout(t){console.log(t);}//標準出力
function myerr(t){console.error(t);}//標準エラー出力
//[no]要素の扱い。数値型
//不明値、異常時:引数そのまま返す　1:数値へ変換
//2:半角SPで分割 4:半角SPで分割し、数値配列へ
//6:1文字で分割  7:1文字で分割し、数値配列へ
//8:半角SPで結合 9:改行で結合 0:文字なしで結合
function myconv(i,no){try{switch(no){case 1:return parseInt(i);case 2:return i.split(" ");case 4:return i.split(" ").map((a)=>Number(a));case 6:return i.split("");case 7:return i.split("").map((a)=>Number(a));case 8:return i.join(" ");case 9:return i.join("\n");case 0:return i.join("");default:return i;}}catch(e){return i;}}
function Main(){
  var one = nextIntArray();
  var N = one[0];
  var K = one[1];
  var tmp = Math.ceil(N / 2);
  if(tmp <= K){
     myout("Yes");
  }else{
     myout("No");
  }
}


function main(input){
    const tmp = input.split(/\n/).map(str=>{return parseInt(str)});
    console.log((tmp[0] + 1) / 2 >=  tmp[1] ? 'YES' : 'NO');
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));


package main

import "fmt"

func main() {
	var n, k int
	fmt.Scan(&n, &k)

	if 1+(k-1)*2 <= n {
		fmt.Println("YES")
	} else {
		fmt.Println("NO")
	}
}


package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

var sc = bufio.NewScanner(os.Stdin)

func next() string {
	sc.Scan()
	return sc.Text()
}

func nextInt() int {
	sc.Scan()
	i, _ := strconv.Atoi(sc.Text())
	return i
}

func nextFloat64() float64 {
	f, _ := strconv.ParseFloat(next(), 64)
	return f
}

func nextInts(n int) []int {
	slice := make([]int, n)
	for i := 0; i < n; i++ {
		slice[i] = nextInt()
	}
	return slice
}

func main() {
	sc.Split(bufio.ScanWords)
	n, k := nextInt(), nextInt()
	if (n+1)/2 >= k {
		fmt.Println("YES")
	} else {
		fmt.Println("NO")
	}
}


package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

func getScanner(fp *os.File) *bufio.Scanner {
	scanner := bufio.NewScanner(fp)
	scanner.Split(bufio.ScanWords)
	scanner.Buffer(make([]byte, 1000005), 1000005)
	return scanner
}

func getNextString(scanner *bufio.Scanner) string {
	scanner.Scan()
	return scanner.Text()
}

func getNextInt(scanner *bufio.Scanner) int {
	i, _ := strconv.Atoi(getNextString(scanner))
	return i
}

func getNextInt64(scanner *bufio.Scanner) int64 {
	i, _ := strconv.ParseInt(getNextString(scanner), 10, 64)
	return i
}

func getNextUint64(scanner *bufio.Scanner) uint64 {
	i, _ := strconv.ParseUint(getNextString(scanner), 10, 64)
	return i
}

func getNextFloat64(scanner *bufio.Scanner) float64 {
	i, _ := strconv.ParseFloat(getNextString(scanner), 64)
	return i
}

func main() {
	fp := os.Stdin
	wfp := os.Stdout
	cnt := 0

	if os.Getenv("MASPY") == "ますピ" {
		fp, _ = os.Open(os.Getenv("BEET_THE_HARMONY_OF_PERFECT"))
		cnt = 3
	}
	if os.Getenv("MASPYPY") == "ますピッピ" {
		wfp, _ = os.Create(os.Getenv("NGTKANA_IS_GENIUS10"))
	}

	scanner := getScanner(fp)
	writer := bufio.NewWriter(wfp)
	solve(scanner, writer)
	for i := 0; i < cnt; i++ {
		fmt.Fprintln(writer, "-----------------------------------")
		solve(scanner, writer)
	}
	writer.Flush()
}

func solve(scanner *bufio.Scanner, writer *bufio.Writer) {
	n := getNextInt(scanner)
	k := getNextInt(scanner)
	if (n+1)/2 < k {
		fmt.Fprintln(writer, "NO")
		return
	}
	fmt.Fprintln(writer, "YES")
}


package main

import (
  "fmt"
)

func main() {
  var n, k int
  fmt.Scanf("%d %d", &n, &k)

  ans := "NO"
  if (n/2 + 1) >= k {
    ans = "YES"
  }
  fmt.Printf("%s\n", ans)
}


package main

import (
	"bufio"
	"fmt"
	"math"
	"os"
	"reflect"
	"sort"
	"strconv"
	"strings"
	// "regexp"
)

/* sort */
type pair struct {
	index  int64
	p1, p2 interface{}
}
type pairs []pair

func (slice pairs) Len() int {
	return len(slice)
}

func (slice pairs) Less(i, j int) bool {
	return slice[i].index < slice[j].index
}

func (slice pairs) Swap(i, j int) {
	slice[i], slice[j] = slice[j], slice[i]
}

/* sort */
type Int64Slice []int64

func (slice Int64Slice) Len() int {
	return len(slice)
}

func (slice Int64Slice) Less(i, j int) bool {
	return slice[i] < slice[j]
}

func (slice Int64Slice) Swap(i, j int) {
	slice[i], slice[j] = slice[j], slice[i]
}
func Int64s(a []int64)                    { sort.Sort(Int64Slice(a)) }
func Int64sSliceAreSorted(a []int64) bool { return sort.IsSorted(Int64Slice(a)) }

const (
	initialBufSize = 1e4
	maxBufSize     = 1e8
	INF            = 1e8
)

var (
	scanner = bufio.NewScanner(os.Stdin)
	writer  = bufio.NewWriter(os.Stdout)
	di      = []int64{-1, 0, 1, 0}
	dj      = []int64{0, -1, 0, 1}
	di8     = []int64{-1, -1, 0, 1, 1, 1, 0, -1}
	dj8     = []int64{0, -1, -1, -1, 0, 1, 1, 1}
)

func main() {
	buf := make([]byte, initialBufSize)
	scanner.Buffer(buf, maxBufSize)
	scanner.Split(bufio.ScanWords)
	N, K := readInt(), readInt()
	if N%2 == 0 {
		if N-K >= 2 {
			fmt.Println("YES")
		} else {
			fmt.Println("NO")
		}
	} else {
		if N-K >= 1 {
			fmt.Println("YES")
		} else {
			fmt.Println("NO")
		}
	}

}

/*==========================================
 *             Library
 *==========================================*/
func NextPermutation(x sort.Interface) bool {
	n := x.Len() - 1
	if n < 1 {
		return false
	}
	j := n - 1
	for ; !x.Less(j, j+1); j-- {
		if j == 0 {
			return false
		}
	}
	l := n
	for !x.Less(j, l) {
		l--
	}
	x.Swap(j, l)
	for k, l := j+1, n; k < l; {
		x.Swap(k, l)
		k++
		l--
	}
	return true
}
func doubleAry(h int64, w int64, init int64) (res [][]int64) {
	res = make([][]int64, h)
	for i := int64(0); i < h; i++ {
		res[i] = make([]int64, w)
		for j := int64(0); j < w; j++ {
			res[i][j] = init
		}
	}
	return
}

func aryEq(a []int64, b []int64) bool {
	return reflect.DeepEqual(a, b)
}

func clone(n []int64) (r []int64) {
	r = make([]int64, len(n))
	for i := 0; i < len(n); i++ {
		r[i] = n[i]
	}
	return
}
func write(s string) {
	writer.WriteString(s)
}

func print() {
	writer.Flush()
}

// scanner.Split(bufio.ScanWords) をコメントアウトしないと使用不可
func readLine() (s string) {
	if scanner.Scan() {
		s = scanner.Text()
	}
	return s
}

func readInt() (read int64) {
	scanner.Scan()
	read, err := strconv.ParseInt(scanner.Text(), 10, 64)
	if err != nil {
		panic(err)
	}
	return
}

func readFloat() (read float64) {
	scanner.Scan()
	read, err := strconv.ParseFloat(scanner.Text(), 64)
	if err != nil {
		panic(err)
	}
	return
}

func readRunes() (read []rune) {
	scanner.Scan()
	for _, v := range scanner.Text() {
		read = append(read, v)
	}
	return
}

func readString() (read string) {
	scanner.Scan()
	read = scanner.Text()
	return
}

func readStrings() (read []string) {
	scanner.Scan()
	for _, v := range scanner.Text() {
		read = append(read, string(v))
	}
	return
}

func s2i(s string) int64 {
	var intVal, e = strconv.ParseInt(s, 10, 64)
	if e != nil {
		panic(e)
	}
	return intVal
}

func i2s(i int64) string {
	var strVal = strconv.FormatInt(i, 10)
	return strVal
}

func s2f(s string) float64 {
	var floatVal, e = strconv.ParseFloat(s, 64)
	if e != nil {
		panic(e)
	}
	return floatVal
}

func abs(i int64) int64 {
	return int64(math.Abs(float64(i)))
}

func max(a ...int64) int64 {
	ans := int64(0)
	for i, v := range a {
		if i == 0 {
			ans = v
		}
		if ans < v {
			ans = v
		}
	}
	return ans
}
func min(a ...int64) int64 {
	ans := int64(0)
	for i, v := range a {
		if i == 0 {
			ans = v
		}
		if ans > v {
			ans = v
		}
	}
	return ans
}

func sum(i []int64) int64 {
	sum := int64(0)
	for _, val := range i {
		sum += val
	}
	return sum
}

func split(s string) []string {
	return strings.Fields(s)
}

func strAry2intAry(strs []string) []int64 {
	var ret = make([]int64, 0, len(strs))
	for _, str := range strs {
		var intVal = s2i(str)
		ret = append(ret, intVal)
	}
	return ret
}

func intAry2strAry(nums []int64) []string {
	var ret = make([]string, 0, len(nums))
	for _, num := range nums {
		var strVal = i2s(num)
		ret = append(ret, strVal)
	}
	return ret
}

func ary2str(strs []string) string {
	return strings.Join(strs, " ")
}

func reverse(res []int64) []int64 {
	for i, j := 0, len(res)-1; i < j; i, j = i+1, j-1 {
		res[i], res[j] = res[j], res[i]
	}
	return res
}
func reverseStr(res []string) []string {
	for i, j := 0, len(res)-1; i < j; i, j = i+1, j-1 {
		res[i], res[j] = res[j], res[i]
	}
	return res
}

func ini(res []int, init int) {
	if len(res) == 0 {
		return
	}
	res[0] = init
	for i := 0; i < len(res); i++ {
		copy(res[i:], res[:i])
	}
}

//
// func regexpExample() {
//     // Your code here!
//     var str = "13:20"
//     r := regexp.MustCompile(`(\d+):(\d+)`)
//     fmt.Println(r.FindStringSubmatch(str))
// }

// type Country struct {
//     gold int
//     silver int
//     blonze int
// }

// // 複数ソートのサンプル
// func stableSortExample() []Country{
//     var country = []Country {
//         {gold:1, silver:2, blonze:3},
//         {gold:1, silver:2, blonze:3},
//         {gold:1, silver:3, blonze:2},
//         {gold:1, silver:3, blonze:3},
//     }
//     sort.SliceStable(country, func(i, j int) bool { return country[i].blonze > country[j].blonze })
//     sort.SliceStable(country, func(i, j int) bool { return country[i].silver > country[j].silver })
//     sort.SliceStable(country, func(i, j int) bool { return country[i].gold > country[j].gold })
//     return country
// }


package main

import "fmt"

func main() {
	var N, K int
	fmt.Scan(&N, &K)
	if N/2+1 >= K {
		fmt.Println("YES")
	} else {
		fmt.Println("NO")
	}
}


n, k = gets.split.map(&:to_i)
puts (2 * k - 1 <= n) ? "YES" : "NO"


#input of int(split by space)
def get_i()
  return gets.chomp.split(" ").map(&:to_i)
end
#input of float(split by space)
def get_f()
  return gets.chomp.split(" ").map(&:to_f)
end
#input of string(split by space)
def get()
  return gets.chomp.split(" ")
end
#input of string(split per one character)
def get_nsp()
  return gets.chomp.split("")
end
#yes or no decision
def yn_judge(bool,y="Yes",n="No")
  return bool ? y : n
end
#create of array
def array(size1,init=nil,size2=-1)
  if size2==-1
    return Array.new(size1){init}
  else
    return Array.new(size2){Array.new(size1){init}}
  end
end

def max(a,b)
    return a>b ? a : b
end

def min(a,b)
    return a>b ? b : a
end

INF=Float::INFINITY

N,K=get_i
if (N+1)/2>=K
    puts "YES"
else
    puts "NO"
end


# frozen_string_literal: true

n, k = gets.split.map(&:to_i)

puts (n / 2.0).ceil >= k ? :YES : :NO


n, k = gets.chomp.split.map(&:to_i)
puts n/k >= 2 ? "YES" : "NO"


N, K = gets.strip.split.map(&:to_i)
puts  (N+1)/2 >= K ? :YES :NO


n, k = gets.split.map(&:to_i)

if n/2+1 >= k
	puts "YES"
else
	puts "NO"
end


#![allow(unused_imports)]
#![allow(unused_macros)]
#![allow(non_snake_case)]
#![allow(dead_code)]
#![allow(unused_variables)]
#![allow(unused_mut)]
use std::collections::{BTreeMap, BTreeSet, BinaryHeap, HashMap, HashSet, VecDeque};
use std::cmp::{max, min, Ordering};

macro_rules! get {
    ($t:ty) => {
        {
            let mut line: String = String::new();
            std::io::stdin().read_line(&mut line).unwrap();
            line.trim().parse::<$t>().unwrap()
        }
    };
    ($($t:ty),*) => {
        {
            let mut line: String = String::new();
            std::io::stdin().read_line(&mut line).unwrap();
            let mut iter = line.split_whitespace();
            (
                $(iter.next().unwrap().parse::<$t>().unwrap(),)*
            )
        }
    };
    ($t:ty; $n:expr) => {
        (0..$n).map(|_|
            get!($t)
        ).collect::<Vec<_>>()
    };
    ($($t:ty),*; $n:expr) => {
        (0..$n).map(|_|
            get!($($t),*)
        ).collect::<Vec<_>>()
    };
    ($t:ty ;;) => {
        {
            let mut line: String = String::new();
            std::io::stdin().read_line(&mut line).unwrap();
            line.split_whitespace()
                .map(|t| t.parse::<$t>().unwrap())
                .collect::<Vec<_>>()
        }
    };
    ($t:ty ;; $n:expr) => {
        (0..$n).map(|_| get!($t ;;)).collect::<Vec<_>>()
    };
}

// N M => let (N, M) = get!(usize, usize)
// A1 B1
// ...
// AQ BQ => let A = get!(usize, usize; Q)

const MOD: u64 = 1000000007;

fn main() {
    let (N, K) = get!(usize, usize);

    let ans: usize = (N + 1) / 2;

    if ans >= K {
        println!("YES");
    } else {
        println!("NO");
    }

}


use std::io::{stdin, Read, StdinLock};
use std::str::FromStr;

fn main() {
    let cin = stdin();
    let cin = cin.lock();
    let mut scan = Scanner::new(cin);
    let n: i64 = scan.read();
    let k: i64 = scan.read();
    println!("{}", if k*2-1<=n {"YES"} else {"NO"});
}

// region template
struct Scanner<'a> {
    cin: StdinLock<'a>,
}

impl<'a> Scanner<'a> {
    fn new(cin: StdinLock<'a>) -> Scanner<'a> {
        Scanner { cin: cin }
    }

    fn read_opt<T: FromStr>(&mut self) -> Option<T> {
        let token = self.cin.by_ref().bytes().map(|c| c.unwrap() as char)
            .skip_while(|c| c.is_whitespace())
            .take_while(|c| !c.is_whitespace())
            .collect::<String>();
        token.parse::<T>().ok()
    }

    fn read<T: FromStr>(&mut self) -> T {
        self.read_opt().unwrap()
    }
}
// endregion


#[allow(unused_imports)]
use std::char::*;
#[allow(unused_imports)]
use std::cmp::*;
use std::io::*;
use std::str::FromStr;
#[allow(unused_imports)]
use std::collections::*;

#[allow(unused_macros)]
macro_rules! debug {
    ($($a:expr),*) => {
        println!(concat!($(stringify!($a), " = {:?}, "),*), $($a),*);
    }
}

fn read<T: FromStr>() -> T {
    let stdin = stdin();
    let stdin = stdin.lock();
    let token: String = stdin
        .bytes()
        .map(|c| c.expect("failed to read char") as char)
        .skip_while(|c| c.is_whitespace())
        .take_while(|c| !c.is_whitespace())
        .collect();
    token.parse().ok().expect("failed to parse token")
}

#[derive(PartialEq, PartialOrd)]
pub struct Total<T>(pub T);

impl<T: PartialEq> Eq for Total<T> {}

impl<T: PartialOrd> Ord for Total<T> {
    fn cmp(&self, other: &Total<T>) -> std::cmp::Ordering {
        self.0.partial_cmp(&other.0).unwrap()
    }
}

//const MAX:usize = 100006;
//const INF:u64 = u64::max_value();

fn main() {
    let n:i32 = read();
    let k:i32 = read();

    println!("{}", if (n+1)/2 >= k {"YES"} else {"NO"});

}


#![allow(unused_imports)]

// language: Rust(1.42.0)
// check available crates on AtCoder at "https://atcoder.jp/contests/language-test-202001"
// My Library Repositry is at "https://github.com/Loptall/prcn_lib"

/*
    青perfほしいよ〜！
*/

// from std...
use std::cmp::{
    max, min, Ordering,
    Ordering::{Equal, Greater, Less},
    Reverse,
};
use std::collections::{BTreeMap, BTreeSet, BinaryHeap, HashMap, HashSet, VecDeque};
use std::convert::TryInto;
use std::fmt;
use std::mem::swap;
use std::num::{NonZeroU32, ParseIntError};
use std::ops::{
    Add, AddAssign, BitAnd, BitAndAssign, BitOr, BitOrAssign, BitXor, BitXorAssign, Div, DivAssign,
    Index, IndexMut, Mul, MulAssign, Neg, Rem, RemAssign, Shl, ShlAssign, Shr, ShrAssign, Sub,
    SubAssign,
};
use std::process::exit;
use std::{f32, f64, i128, i16, i32, i64, i8, isize, u128, u16, u32, u64, u8, usize};

// Dep' crates are...
use itertools::*;
use itertools_num::*;
use lazy_static::lazy_static;
use maplit::{btreemap, btreeset, hashmap, hashset};
use num_bigint::{BigInt, BigUint};
use num_complex::Complex;
use num_integer::{binomial, gcd, lcm, multinomial, Integer};
use num_rational::Rational;
use num_traits::{
    clamp, one, pow, zero, Num, NumAssignOps, NumOps, One, Pow, Signed, Unsigned, Zero,
};
use permutohedron::Heap;
use proconio::{
    derive_readable, fastout, input, is_stdin_empty,
    marker::{Bytes, Chars, Isize1, Usize1},
};
use rand::random;

pub trait Visualize {
    fn visualize(&self, split: &str);
    fn continuous(&self) {
        self.visualize("");
    }
    fn spaces(&self) {
        self.visualize(" ");
    }
    fn lines(&self) {
        self.visualize("\n");
    }
}
macro_rules ! impl_vis_for_sized {($ ($ t : ty ) ,+ ) => {$ (impl Visualize for $ t {fn visualize (& self , _split : & str ) {print ! ("{}" , self ) ; } } ) + } ; }
impl_vis_for_sized! {usize , u8 , u16 , u32 , u64 , u128 , isize , i8 , i16 , i32 , i64 , i128 , String , & str }
impl<T: fmt::Display> Visualize for [T] {
    fn visualize(&self, split: &str) {
        print!("{}", self.iter().join(split));
    }
}
/// macro to output answer improved to println
///
/// this macro will print '\n' at the last.
///
/// # Patterns
///
/// `,`, it means one space, it formats the elements, which is before, space-split.
/// And insert a space after the prefix, unless it is at last.
///
/// `=>`, it means empty string, it formats the element, witch is before, without any split.
/// And insert nothing between two element.
///
/// `;`, it means newline(\n), it formats the element, witch is before, newline-split.
/// And insert a newline after the prefix, unless it is at last.
///
/// # Eample
///
/// ```
/// #[test]
/// fn vis_test() {
///     let a = 1;
///     let b = 2;
///     let c = 3;
///
///     let v = vec!['a', 'b', 'c'];
///
///     // single element test ...
///
///     vis!(a); // 1\n
///     vis!(a,); // 1\n
///     vis!(a =>); // 1\n
///     vis!(a;); // 1\n
///
///     println!();
///
///     vis!(a + b); // 3\n
///
///     println!();
///
///     vis!(v); // a b c\n
///     vis!(v,); // a b c\n
///     vis!(v =>); // abc\n
///     vis!(v;); // a\nb\nc\n
///
///     println!();
///
///     // multi elements connected by common operater test ...
///
///     println!();
///
///     vis!(a, b); // 1 2\n
///     vis!(a, b, c); // 1 2 3\n
///     vis!(a, b, c;); // 1 2 3\n
///
///     println!();
///
///     vis!(a => b); // 12\n
///     vis!(a => b => c); // 123\n
///     vis!(a => b => c ,); // 123\n
///
///     println!();
///
///     vis!(a; b); // 1\n2\n
///     vis!(a; b; c); // 1\n2\n3\n
///     vis!(a; b; c =>); // 1\n2\n3\n
///
///     println!();
///
///     // multi elements connected by different operater test ...
///
///     vis!(a, b; c); // 1 2\n3\n
///     vis!(a; b, c); // 1\n2 3\n
///     vis!(a => b, c); // 12 3\n
///     vis!(a; b => c); // 1\n23\n
///
///     println!();
///
///     vis!(a, v); // 1 a b c\n;
///     vis!(a, v;); // 1 a\nb\nc\n;
///     vis!(a => v =>); // 1abc\n;
///
///     println!("\d");
///     // panic!()
/// }
/// ```
#[macro_export]
macro_rules ! vis {() => {println ! () ; } ; ($ last : expr ; ) => {$ last . lines () ; vis ! () } ; ($ last : expr => ) => {$ last . continuous () ; vis ! () ; } ; ($ last : expr $ (, ) ? ) => {$ last . spaces () ; vis ! () ; } ; ($ first : expr ; $ ($ rest : tt ) * ) => {$ first . lines () ; println ! () ; vis ! ($ ($ rest ) * ) ; } ; ($ first : expr => $ ($ rest : tt ) * ) => {$ first . continuous () ; vis ! ($ ($ rest ) * ) ; } ; ($ first : expr , $ ($ rest : tt ) * ) => {$ first . spaces () ; print ! (" " ) ; vis ! ($ ($ rest ) * ) ; } ; }

pub const MOD10E9_7: usize = 1000000007;
pub const MOD99_: usize = 998244353;
pub const MAX: usize = std::usize::MAX;
pub const PI: f64 = f64::consts::PI;
pub const ASCII_A: u8 = 65;
pub const ASCII_0: u8 = 48;

// code...
// #[fastout]
fn main() {
    input! {
        n: usize, k: usize
    }

    if (n + 1) / 2 >= k {
        vis!("Yes");
    } else {
        vis!("No");
    }
}


#[allow(unused_imports)]
use std::char::*;
#[allow(unused_imports)]
use std::cmp::*;
use std::io::*;
use std::str::FromStr;
#[allow(unused_imports)]
use std::collections::*;

#[allow(unused_macros)]
macro_rules! debug {
    ($($a:expr),*) => {
        println!(concat!($(stringify!($a), " = {:?}, "),*), $($a),*);
    }
}

fn read<T: FromStr>() -> T {
    let stdin = stdin();
    let stdin = stdin.lock();
    let token: String = stdin
        .bytes()
        .map(|c| c.expect("failed to read char") as char)
        .skip_while(|c| c.is_whitespace())
        .take_while(|c| !c.is_whitespace())
        .collect();
    token.parse().ok().expect("failed to parse token")
}

#[derive(PartialEq, PartialOrd)]
pub struct Total<T>(pub T);

impl<T: PartialEq> Eq for Total<T> {}

impl<T: PartialOrd> Ord for Total<T> {
    fn cmp(&self, other: &Total<T>) -> std::cmp::Ordering {
        self.0.partial_cmp(&other.0).unwrap()
    }
}

//const MAX:usize = 100006;
//const INF:u64 = u64::max_value();

fn main() {
    let n:i32 = read();
    let k:i32 = read();

    println!("{}", if n/2+1 >= k {"YES"} else {"NO"});

}


#![allow(unused_imports)]
use std::cmp::{max, min};
use std::collections::{HashMap, HashSet, VecDeque};

//{{{
// https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8
#[macro_export]
macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
        let mut iter = $s.split_whitespace();
        let mut next = || { iter.next().unwrap() };
        $crate::input_inner!{next, $($r)*}
    };
    ($($r:tt)*) => {
        let stdin = std::io::stdin();
        let mut bytes = std::io::Read::bytes(std::io::BufReader::new(stdin.lock()));
        let mut next = move || -> String{
            bytes
                .by_ref()
                .map(|r|r.unwrap() as char)
                .skip_while(|c|c.is_whitespace())
                .take_while(|c|!c.is_whitespace())
                .collect()
        };
        input_inner!{next, $($r)*}
    };
}

#[doc(hidden)]
#[macro_export]
macro_rules! input_inner {
    ($next:expr) => {};
    ($next:expr, ) => {};

    ($next:expr, $var:ident : $t:tt $($r:tt)*) => {
        let $var = $crate::read_value!($next, $t);
        input_inner!{$next $($r)*}
    };
}

#[doc(hidden)]
#[macro_export]
macro_rules! read_value {
    ($next:expr, ( $($t:tt),* )) => {
        ( $($crate::read_value!($next, $t)),* )
    };

    ($next:expr, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($next, $t)).collect::<Vec<_>>()
    };

    ($next:expr, chars) => {
        read_value!($next, String).chars().collect::<Vec<char>>()
    };

    ($next:expr, usize1) => {
        read_value!($next, usize) - 1
    };

    ($next:expr, $t:ty) => {
        $next().parse::<$t>().expect("Parse error")
    };
}
//}}}

fn main() {
    input! {
        n: usize,
        k: usize,
    }
    let mut cnt = 0;
    for i in 1..n + 1 {
        if i % 2 == 1 {
            cnt += 1;
        }
    }
    if cnt >= k {
        println!("YES");
    } else {
        println!("NO");
    }
}


let i=readLine()!.characters.split(" ").map{Int(String($0))!},N=i[0],K=i[1]
print(N<2*K-1 ?"NO":"YES")


let i=readLine()!.characters.split(" ").map{Int(String($0))!},N=i[0],K=i[1]
print(N>2*K+1 ?"YES":"NO")


let i=readLine()!.characters.split(" ").map{Int(String($0))!}
print(i[0]<i[1]-1 ?"NO":"YES")


let i=readLine()!.characters.split(" ").map{Int(String($0))!}
print(i[0]<i[1] ?"NO":"YES")


function Main(input: string) {
  const inputs = input.split(' '),
    len = inputs.length
  let N, K

  if (len > 2 || len === 0) {
    console.log('NO')
    return
  }

  for (let i = 0; i < len; i++) {
    if (inputs[i].indexOf('.') !== -1) {
      console.log('NO')
      return
    }
  }

  try {
    N = parseInt(inputs[0], 10)
    K = parseInt(inputs[1], 10)
  } catch (e) {
    console.log('NO')
    return
  }
  const V = Math.ceil(N / 2)

  if (V >= K) {
    console.log('YES')
    return
  }

  console.log('NO')
  return
}
Main(require('fs').readFileSync('/dev/stdin', 'utf8'))


"use strict";
const Main = (input) =>{
   let xs = input.trim().split(' ').map(v=>parseInt(v,10));
   let N = xs[0];
   let K = xs[1];

   if((N+1)/2 >= K){
     console.log('YES');
   }else{
     console.log('NO');
   }
}
Main(require('fs').readFileSync('/dev/stdin','utf8'));


function main(arg) {
    const [_n , _k] = arg.replace(/\r?\n/g,"").split(" ")
    const n = Number(_n)
    const k = Number(_k)

    if(n + 1 - (k * 2) >= 0){
        console.log("YES")
    }else{
        console.log("NO")
    }
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));


"use strict";
const Main = (input) =>{
   let xs = input.trim().split(' ').map(v=>parseInt(v,10));
   let N = xs[0];
   let K = xs[1];

   if(N+1>2*K){
     console.log('YES');
   }else{
     console.log('NO');
   }
}
Main(require('fs').readFileSync('/dev/stdin','utf8'));


"use strict";
const Main = (input) =>{
   let xs = input.trim().split(' ').map(v=>parseInt(v,10));
   let N = xs[0];
   let K = xs[1];

   if(N+1>2*K){
     console.log('YES');
   }else{
     console.log('NO');
   }
}
Main(require('fs').readFileSync('/dev/stdin','utf8'));N+1<2*K


"use strict";
const Main = (input) =>{
   let xs = input.trim().split(' ').map(v=>parseInt(v,10));
   let N = xs[0];
   let K = xs[1];

   if(N>=(2*K-1)+1){
     console.log('YES');
   }else{
     console.log('NO');
   }
}
Main(require('fs').readFileSync('/dev/stdin','utf8'));


S=input()
T=input()
if S==T[:-1]:
    print("Yes")
else:
    print("No")


s = input()
t = input()

if s == t[:len(s)] and len(s) == len(t) - 1:
    print('Yes')
else:
    print('No')


s = input()
t = input()

if s == t[:-1]:
  print('Yes')
else:
  print('No')


S=input()
T=input()
yes=True
l=len(S)
for i in range l:
  if S[i]!=T[i]:
    yes=False
    break
if yes:
  print("Yes")
else:
  print("No")


a,b,c,k=map(int,input().split())
ans=a
if k-a<=0:
    print(k)
    exit()
if k-a-b<=0:
    print(ans)
    exit()
if k-a-b-c<0:
    ans=ans+(k-a-b)*(-1)
    print(ans)
else:
    ans=ans-c
    print(ans)


S = input()
T = input()
if S in T:
    ans = 'Yes'
else:
    ans = 'No'
print(ans)


import java.io. *;
import java.util.*;
public class Main {

    static int visited[];
    static ArrayList<ArrayList<Integer>> adjlist;
    static class edge implements  Comparator<edge>{
        int dest;
        int cost;

        public edge(int dest, int cost) {
            this.dest = dest;
            this.cost = cost;
        }

        @Override
        public int compare(edge o1, edge o2) {
            return o1.cost-o2.cost;
        }
    }

    static int dist[];
    static int nodesinSubtree[];
    static int color[];
    static ArrayList<Integer> res1;
    static ArrayList<Integer> res2;

    static class Graph{
        int V;
        ArrayList<ArrayList<edge>> adj;
        PriorityQueue<edge> pq;

        public Graph(int V){
            this.V = V;
            adj = new ArrayList<>(V);
            pq = new PriorityQueue<>(V,new edge(-1,-1));
            dist = new int[V];
            nodesinSubtree = new int[V];
            color = new int[V];
            Arrays.fill(color,-1);
            for(int i=0; i<V; i++){
                dist[i] = Integer.MAX_VALUE;
                adj.add(i,new ArrayList<>());
            }
        }

        void addedge(int u, int v, int w ){
            adj.get(u).add(new edge(v,w));
            //adj.get(v).add(new edge(u,w));
        }

        void rDfs(int src, int e){
            //nodes in a subtree
            nodesinSubtree[src] = 1;
            for(int i=0; i<adj.get(src).size(); i++){
                if(adj.get(src).get(i).dest==e){
                    continue;
                }
                rDfs(adj.get(src).get(i).dest,src);
                nodesinSubtree[src]+=nodesinSubtree[adj.get(src).get(i).dest];
            }
        }

        void uBFS(int src){
            Queue<edge> q = new LinkedList<>();
            int color[] = new int[V];
            q.add(new edge(src,0));
            color[src] = 1;
            while (!q.isEmpty()){
                int u = q.poll().dest;
                for(int i=0; i<adj.get(u).size(); i++){
                    if(color[adj.get(u).get(i).dest]==0){
                        color[adj.get(u).get(i).dest] = color[u]==1?2:1;
                        q.add(new edge(adj.get(u).get(i).dest,0));
                    }
                }
            }
        }

        int DFS(int src){
            Stack<edge> st = new Stack<>();
            boolean visited[] = new boolean[V];
            visited[src] = true;
            st.push(new edge(src,0));
            dist[src] = 0;
            color[src] = 0;
            while (!st.empty()){
                int u = st.peek().dest;
                st.pop();
                for(int i=0; i<adj.get(u).size(); i++){
                    if(color[adj.get(u).get(i).dest]==-1 ) {
                        if (color[u] == 0) {
                            color[adj.get(u).get(i).dest] = 1;
                        } else {
                            color[adj.get(u).get(i).dest] = 0;
                        }
                        st.push(new edge(adj.get(u).get(i).dest,0));
                    }else{
                        if(color[u]==0 && color[adj.get(u).get(i).dest]==0){
                            return -1;
                        }
                        if(color[u]==1 && color[adj.get(u).get(i).dest]==1){
                            return -1;
                        }
                    }
                }
            }
            return 0;
        }
    }

/*
        void dijkstra(int src){
            for(int i=0; i<V; i++){
                dist[i] = Integer.MAX_VALUE;
            }
            dist[src] = 0;
            pq.add(new edge(src,0));
            while (!pq.isEmpty()){
                int u = pq.poll().dest;
                for(int i=0; i<adj.get(u).size(); i++){
                    int v = adj.get(u).get(i).dest;
                    int w = adj.get(u).get(i).cost;
                    if(dist[u]+w<=dist[v]){
                        dist[v] = dist[u] + w;
                        pq.add(new edge(v,dist[v]));
                    }
                }
            }

        }

    }

 */

    static  int I[];
    static  int  L[];
    static void LIS(int n, int arr[]){
        I = new int[n+1];
        L = new int[n];
        I[0] = Integer.MIN_VALUE;
        for(int i=1;i<=n; i++){
            I[i] = Integer.MAX_VALUE;
        }
        int lisLength = 1;

        for(int i=n-1; i>=0; i--) {
            int low = 1;
            int high = lisLength;
            int mid = 0;
            while (low < high) {
                mid = (low + high) >> 1;
                if (I[mid] <= arr[i]) {
                    high = mid;
                } else {
                    low = mid + 1;
                }
            }
            I[high] = arr[i];
            L[i] = high;
            if(lisLength<=high){
                lisLength++;
            }
        }
    }

    public static long gcd(long a, long b)
    {
        if (a == 0)
            return b;

        return gcd(b%a, a);
    }

    public static long lcm(long a, long b)
    {
        return (a*b)/gcd(a, b);
    }

    static long nCr(long n, long r)
    {
        return fact(n) / (fact(r) * fact(n - r));
    }

    // Returns factorial of n
    static long fact(long n)
    {
        long res = 1;
        for (int i = 2; i <= n; i++)
            res = (res * i)%MOD;
        return res;
    }

    static int MOD = 1000000007;
    static int power(int x, int y, int p)
    {

        // Initialize result
        int res = 1;

        // Update x if it is more than or
        // equal to p
        x = x % p;

        while (y > 0)
        {

            // If y is odd, multiply x
            // with result
            if (y % 2 == 1)
                res = (res * x) % p;

            // y must be even now
            y = y >> 1; // y = y/2
            x = (x * x) % p;
        }

        return res;
    }

    // Returns n^(-1) mod p
    static int modInverse(int n, int p)
    {
        return power(n, p-2, p);
    }

    static int nCrModPFermat(int n, int r,
                             int p)
    {

        if (r == 0)
            return 1;

        int[] fac = new int[n+1];
        fac[0] = 1;

        for (int i = 1 ;i <= n; i++)
            fac[i] = fac[i-1] * i % p;

        return (fac[n]* modInverse(fac[r], p)
                % p * modInverse(fac[n-r], p)
                % p) % p;
    }
    public static long log2(long N)
    {

        long result = (long)(Math.log(N) / Math.log(2));

        return result;
    }
    static class team implements Comparator<team>{
        long id;
        int m;

        public team(long id, int m) {
            this.id = id;
            this.m = m;
        }

        @Override
        public int compare(team o1, team o2) {
            return o2.m-o1.m;
        }
    }

    static int findParent(int dsu[], int parent){
        if(dsu[parent]<0){
            return parent;
        }
        return findParent(dsu,dsu[parent]);
    }

    static int cnt[];

    public static void main(String[] args) {
        FastReader sc = new FastReader(System.in);
        PrintWriter pw = new PrintWriter(System.out);

        String s = sc.next();
        String t = sc.next();

        for(int i=0; i<s.length(); i++){
            if(s.charAt(i)!=t.charAt(i)){
                pw.println("No");
                pw.close();
                return;
            }
        }
        pw.println("Yes");

        pw.close();

    }

    static void debug(Object...obj) {
        System.err.println(Arrays.deepToString(obj));
    }

    static class FastReader {
        InputStream is;
        private byte[] inbuf = new byte[1024];
        private int lenbuf = 0, ptrbuf = 0;

        public FastReader(InputStream is) {
            this.is = is;
        }

        public int readByte(){
            if(lenbuf == -1)throw new InputMismatchException();
            if(ptrbuf >= lenbuf){
                ptrbuf = 0;
                try {
                    lenbuf = is.read(inbuf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if(lenbuf <= 0)
                    return -1;
            }
            return inbuf[ptrbuf++];
        }
        public boolean isSpaceChar(int c) {
            return !(c >= 33 && c <= 126);
        }
        public int skip() {
            int b;
            while ((b = readByte()) != -1 && isSpaceChar(b)) ;
            return b;
        }
        public String next(){
            int b = skip();
            StringBuilder sb = new StringBuilder();
            while(!(isSpaceChar(b))) {
                sb.appendCodePoint(b);
                b = readByte();
            }
            return sb.toString();
        }
        public String nextLine(){
            int b = readByte();
            StringBuilder sb = new StringBuilder();
            while(b != '\n' || b != '\r'){
                sb.appendCodePoint(b);
            }
            return sb.toString();
        }
        public int nextInt() {
            int num = 0, b;
            boolean minus = false;
            while ((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-')) ;
            if (b == '-') {
                minus = true;
                b = readByte();
            }
            while (true) {
                if (b >= '0' && b <= '9') {
                    num = (num << 3) + (num << 1) + (b - '0');
                } else {
                    return minus ? -num : num;
                }
                b = readByte();
            }
        }
        public long nextLong() {
            long num = 0;
            int b;
            boolean minus = false;
            while ((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-')) ;
            if (b == '-') {
                minus = true;
                b = readByte();
            }
            while (true) {
                if (b >= '0' && b <= '9') {
                    num = (num << 3) + (num << 1) + (b - '0');
                } else {
                    return minus ? -num : num;
                }
                b = readByte();
            }
        }
        public double nextDouble() {
            return Double.parseDouble(next());
        }
        public char[] next(int n){
            char[] buf = new char[n];
            int b = skip(), p = 0;
            while (p < n && !(isSpaceChar(b))) {
                buf[p++] = (char) b;
                b = readByte();
            }
            return n == p ? buf : Arrays.copyOf(buf, p);
        }
        public char nextChar () {
            return (char) skip();
        }
    }
}


import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

public class Main {
  private static class FastScanner {
    private BufferedReader reader = null;
    private StringTokenizer tokenizer = null;

    public FastScanner(InputStream in) {
      reader = new BufferedReader(new InputStreamReader(in));
      tokenizer = null;
    }

    public String next() {
      if (tokenizer == null || !tokenizer.hasMoreTokens()) {
        try {
          tokenizer = new StringTokenizer(reader.readLine());
        } catch (IOException e) {
          throw new RuntimeException(e);
        }
      }
      return tokenizer.nextToken();
    }

    public String nextLine() {
      if (tokenizer == null || !tokenizer.hasMoreTokens()) {
        try {
          return reader.readLine();
        } catch (IOException e) {
          throw new RuntimeException(e);
        }
      }

      return tokenizer.nextToken("\n");
    }

    public long nextLong() {
      return Long.parseLong(next());
    }

    public int nextInt() {
      return Integer.parseInt(next());
    }

    public double nextDouble() {
      return Double.parseDouble(next());
    }

    public int[] nextIntArray(int n) {
      int[] a = new int[n];
      for (int i = 0; i < n; i++)
        a[i] = nextInt();
      return a;
    }

    public long[] nextLongArray(int n) {
      long[] a = new long[n];
      for (int i = 0; i < n; i++)
        a[i] = nextLong();
      return a;
    }
  }

  public static void main(String[] args) {
    FastScanner sc = new FastScanner(System.in);
    String s = sc.next();
    String t = sc.next();
    System.out.println(t.startsWith(s) ? "Yes" : "No");
  }
}


import java.io.IOException;
import java.io.InputStream;
import java.util.NoSuchElementException;

public class Main {

	public static void main(String[] args){
		FastScanner sc = new FastScanner();
		String a = sc.next();
		String b = sc.next();

		b = b.substring(0,b.length() - 1);

		System.out.println(a.equals(b) ? "Yes" : "No");
	}
}

class FastScanner {
    private final InputStream in = System.in;
    private final byte[] buffer = new byte[1024];
    private int ptr = 0;
    private int buflen = 0;
    private boolean hasNextByte() {
        if (ptr < buflen) {
            return true;
        }else{
            ptr = 0;
            try {
                buflen = in.read(buffer);
            } catch (IOException e) {
                e.printStackTrace();
            }
            if (buflen <= 0) {
                return false;
            }
        }
        return true;
    }
    private int readByte() { if (hasNextByte()) return buffer[ptr++]; else return -1;}
    private static boolean isPrintableChar(int c) { return 33 <= c && c <= 126;}
    public boolean hasNext() { while(hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++; return hasNextByte();}
    public String next() {
        if (!hasNext()) throw new NoSuchElementException();
        StringBuilder sb = new StringBuilder();
        int b = readByte();
        while(isPrintableChar(b)) {
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }
    public long nextLong() {
        if (!hasNext()) throw new NoSuchElementException();
        long n = 0;
        boolean minus = false;
        int b = readByte();
        if (b == '-') {
            minus = true;
            b = readByte();
        }
        if (b < '0' || '9' < b) {
            throw new NumberFormatException();
        }
        while(true){
            if ('0' <= b && b <= '9') {
                n *= 10;
                n += b - '0';
            }else if(b == -1 || !isPrintableChar(b)){
                return minus ? -n : n;
            }else{
                throw new NumberFormatException();
            }
            b = readByte();
        }
    }
    public int nextInt() {
        long nl = nextLong();
        if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE) throw new NumberFormatException();
        return (int) nl;
    }
    public double nextDouble() { return Double.parseDouble(next());}
}


import java.util.Scanner;
public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    String S = sc.next();
    String T = sc.next();
    for(int i=0; i<S.length()-1; i++) {
      if(S.charAt(i) != T.charAt(i)) {
        System.out.println("No");
      } else if(S.charAt(i) == T.charAt(i)) {
        System.out.println("Yes");
      }
    }
  }
}


import java.util.Scanner;
public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    String S = sc.next();
    String T = sc.next();
    for(int i=0; i<=S.length()-1; i++) {
      if(S.charAt(i) != T.charAt(i)) {
        System.out.println("No");
      } else if(S.charAt(i) == T.charAt(i)) {
        System.out.println("Yes");
      }
    }
  }
}


import java.util.Scanner;
public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    String S = sc.next();
    String T = sc.next();
    for(int i=0; i<10; i++) {
      if(S.charAt(i) != T.charAt(i)) {
        System.out.println("No");
      } else if(S.charAt(i) == T.charAt(i)) {
        System.out.println("Yes");
      }
    }
  }
}


#include <cstdio>
#include <cstring>
using namespace std;
int length,flag;
char oID[10],nID[11];
int main ()
{
	scanf("%s%s",oID,nID);
	length=strlen(oID);
	for (int i=0;i<length;++i)
	{
		if (oID[i]!=nID[i])
		{
			flag=1;
			break;
		}
	}
	if (flag==0) printf("Yes");
	else printf("No");
	return 0;
}


#include <stdio.h>
#include <string.h>

#define EQUAL 1
#define NOT_EQ 0

int main(){
    char S[20],T[20];
    int i, flag= EQUAL;

    scanf("%s", S);
    scanf("%s", T);

    auto T_len = strlen(T);
    auto S_len = strlen(S);

    if(T_len == S_len+1 && strncmp(T,S,S_len)==0){
        printf("Yes");
    }else{
        printf("No");
    }
}


#include <stdio.h>
#include <string.h>
int main(){
	char a[15], b[15];
	scanf("%s%s", a, b);
	int n = strlen(b);
	if(strncmp(a, b, n-1) == 0) printf("Yes\n");
	else printf("No\n");
	return 0;
}


#include <bits/stdc++.h>
#include <iostream>
#include <math.h>    //pow(x,y)=x^y 99999とかの場合+1するif文
#include <algorithm> //sort(a.begin(), a.end());reverse(a.begin(), a.end());
#include <ctime>     //実行時間を測る
#define ll long long
#define vecvec(h, w, name) vector<vector<ll>> name(h, vector<ll>(w));
#define rep(init, i, n) for (ll i = init; i < (n); i++)
#define rev(s) reverse(s.begin(), s.end())
#define sor(v) sort(v.begin(), v.end()) //昇順
#define PI 3.14159265358979323846264338327950L
//コード自動整形 Shift + Option + F @vscode
//変数名一括置換　command+fn+f2 @vscode
using namespace std;
using vec = vector<ll>;
//function
ll facctorialMethod(ll k);     //階乗を出力する
ll modpow(ll a, ll n, ll mod); // a^n mod を計算する
ll gcd(ll a, ll b);            //最大公約数
ll lcm(ll a, ll b);            //最小公倍数
ll vecmax(vector<ll> v);       //１次元配列の最大値を返すO(NlogN)
ll vecmin(vector<ll> v);       //１次元配列の最小値を返すO(NlogN)
//

//struct
// UnionFind
// coding: https://youtu.be/TdR816rqc3s?t=726
// comment: https://youtu.be/TdR816rqc3s?t=6822
struct UnionFind
{
  vector<ll> d;
  UnionFind(ll n = 0) : d(n, -1) {}
  ll find(ll x)
  { //根っこを返す
    if (d[x] < 0)
      return x;
    return d[x] = find(d[x]); //根っこの場所を貼り付ける
  }
  bool unite(ll x, ll y)
  { //くっつける操作、連結成分の情報整理 ABC177,157D参照
    x = find(x);
    y = find(y);
    if (x == y)
      return false;
    if (d[x] > d[y])
      swap(x, y); //dはマイナスをかけたサイズだからxの方がサイズ小さいようにする
    d[x] += d[y];
    d[y] = x;
    return true;
  }
  //find(i)でi番目の属しているグループ番号を出力
  bool same(ll x, ll y) { return find(x) == find(y); } //同じ集合に属しているかを判定
  ll size(ll x) { return -d[find(x)]; }                //あるID、xが所属するグループに所属するIDの数を得る ABC177,157D参照
};
//

/////main/////
int main()
{
  int clock_on = 0; //提出時は0!!!!!!!!!!!!!!!!!
  int time_clock = clock();
  //
  string S,T;
  cin>>S>>T;
  rep(0,i,(ll) S.size()-1){
   if(S.at(i)!=T.at(i)) {cout<<"No"<<endl;return 0;}
  }
cout<<"Yes"<<endl;

  //
  if (clock_on == 1)
    printf("Execution Time: %.4lf sec\n", 1.0 * (clock() - time_clock) / CLOCKS_PER_SEC);
  return 0;
}
/////main/////

/////function/////
//階乗を出力する
ll facctorialMethod(ll k)
{
  ll sum = 1;
  for (ll i = 1; i <= k; ++i)
  {
    sum *= i;
  }
  return sum;
}

// a^n mod を計算する
ll modpow(ll a, ll n, ll mod)
{
  ll res = 1;
  while (n > 0)
  {
    if (n & 1)
      res = res * a % mod;
    a = a * a % mod;
    n >>= 1;
  }
  return res;
}

//最大公約数
ll gcd(ll a, ll b)
{
  if (a % b == 0)
  {
    return b;
  }
  else
  {
    return gcd(b, a % b);
  }
}

//最小公倍数
ll lcm(ll a, ll b)
{
  return a * b / gcd(a, b);
}

//１次元配列の最大値を返すO(NlogN)
ll vecmax(vector<ll> v)
{
  sor(v);
  return v.at(v.size() - 1);
}

//１次元配列の最小値を返すO(NlogN)
ll vecmin(vector<ll> v)
{
  sor(v);
  return v.at(0);
}


#include <bits/stdc++.h>
#include <iostream>
#include <math.h>    //pow(x,y)=x^y 99999とかの場合+1するif文
#include <algorithm> //sort(a.begin(), a.end());reverse(a.begin(), a.end());
#include <ctime>     //実行時間を測る
#define ll long long
#define vecvec(h, w, name) vector<vector<ll>> name(h, vector<ll>(w));
#define rep(init, i, n) for (ll i = init; i < (n); i++)
#define rev(s) reverse(s.begin(), s.end())
#define sor(v) sort(v.begin(), v.end()) //昇順
#define PI 3.14159265358979323846264338327950L
//コード自動整形 Shift + Option + F @vscode
//変数名一括置換　command+fn+f2 @vscode
using namespace std;
using vec = vector<ll>;
//function
ll facctorialMethod(ll k);     //階乗を出力する
ll modpow(ll a, ll n, ll mod); // a^n mod を計算する
ll gcd(ll a, ll b);            //最大公約数
ll lcm(ll a, ll b);            //最小公倍数
ll vecmax(vector<ll> v);       //１次元配列の最大値を返すO(NlogN)
ll vecmin(vector<ll> v);       //１次元配列の最小値を返すO(NlogN)
//

//struct
// UnionFind
// coding: https://youtu.be/TdR816rqc3s?t=726
// comment: https://youtu.be/TdR816rqc3s?t=6822
struct UnionFind
{
  vector<ll> d;
  UnionFind(ll n = 0) : d(n, -1) {}
  ll find(ll x)
  { //根っこを返す
    if (d[x] < 0)
      return x;
    return d[x] = find(d[x]); //根っこの場所を貼り付ける
  }
  bool unite(ll x, ll y)
  { //くっつける操作、連結成分の情報整理 ABC177,157D参照
    x = find(x);
    y = find(y);
    if (x == y)
      return false;
    if (d[x] > d[y])
      swap(x, y); //dはマイナスをかけたサイズだからxの方がサイズ小さいようにする
    d[x] += d[y];
    d[y] = x;
    return true;
  }
  //find(i)でi番目の属しているグループ番号を出力
  bool same(ll x, ll y) { return find(x) == find(y); } //同じ集合に属しているかを判定
  ll size(ll x) { return -d[find(x)]; }                //あるID、xが所属するグループに所属するIDの数を得る ABC177,157D参照
};
//

/////main/////
int main()
{
  int clock_on = 0; //提出時は0!!!!!!!!!!!!!!!!!
  int time_clock = clock();
  //
  string S,T;
  cin>>S>>T;
  rep(0,i,(ll) S.size()-1){
   if(S.at(i)!=S.at(i)) {cout<<"No"<<endl;return 0;}
  }
cout<<"Yes"<<endl;

  //
  if (clock_on == 1)
    printf("Execution Time: %.4lf sec\n", 1.0 * (clock() - time_clock) / CLOCKS_PER_SEC);
  return 0;
}
/////main/////

/////function/////
//階乗を出力する
ll facctorialMethod(ll k)
{
  ll sum = 1;
  for (ll i = 1; i <= k; ++i)
  {
    sum *= i;
  }
  return sum;
}

// a^n mod を計算する
ll modpow(ll a, ll n, ll mod)
{
  ll res = 1;
  while (n > 0)
  {
    if (n & 1)
      res = res * a % mod;
    a = a * a % mod;
    n >>= 1;
  }
  return res;
}

//最大公約数
ll gcd(ll a, ll b)
{
  if (a % b == 0)
  {
    return b;
  }
  else
  {
    return gcd(b, a % b);
  }
}

//最小公倍数
ll lcm(ll a, ll b)
{
  return a * b / gcd(a, b);
}

//１次元配列の最大値を返すO(NlogN)
ll vecmax(vector<ll> v)
{
  sor(v);
  return v.at(v.size() - 1);
}

//１次元配列の最小値を返すO(NlogN)
ll vecmin(vector<ll> v)
{
  sor(v);
  return v.at(0);
}


#include <bits/stdc++.h>
#include <iostream>
#include <math.h>    //pow(x,y)=x^y 99999とかの場合+1するif文
#include <algorithm> //sort(a.begin(), a.end());reverse(a.begin(), a.end());
#include <ctime>     //実行時間を測る
#define ll long long
#define vecvec(h, w, name) vector<vector<ll>> name(h, vector<ll>(w));
#define rep(init, i, n) for (ll i = init; i < (n); i++)
#define rev(s) reverse(s.begin(), s.end())
#define sor(v) sort(v.begin(), v.end()) //昇順
#define PI 3.14159265358979323846264338327950L
//コード自動整形 Shift + Option + F @vscode
//変数名一括置換　command+fn+f2 @vscode
using namespace std;
using vec = vector<ll>;
//function
ll facctorialMethod(ll k);     //階乗を出力する
ll modpow(ll a, ll n, ll mod); // a^n mod を計算する
ll gcd(ll a, ll b);            //最大公約数
ll lcm(ll a, ll b);            //最小公倍数
ll vecmax(vector<ll> v);       //１次元配列の最大値を返すO(NlogN)
ll vecmin(vector<ll> v);       //１次元配列の最小値を返すO(NlogN)
//

//struct
// UnionFind
// coding: https://youtu.be/TdR816rqc3s?t=726
// comment: https://youtu.be/TdR816rqc3s?t=6822
struct UnionFind
{
  vector<ll> d;
  UnionFind(ll n = 0) : d(n, -1) {}
  ll find(ll x)
  { //根っこを返す
    if (d[x] < 0)
      return x;
    return d[x] = find(d[x]); //根っこの場所を貼り付ける
  }
  bool unite(ll x, ll y)
  { //くっつける操作、連結成分の情報整理 ABC177,157D参照
    x = find(x);
    y = find(y);
    if (x == y)
      return false;
    if (d[x] > d[y])
      swap(x, y); //dはマイナスをかけたサイズだからxの方がサイズ小さいようにする
    d[x] += d[y];
    d[y] = x;
    return true;
  }
  //find(i)でi番目の属しているグループ番号を出力
  bool same(ll x, ll y) { return find(x) == find(y); } //同じ集合に属しているかを判定
  ll size(ll x) { return -d[find(x)]; }                //あるID、xが所属するグループに所属するIDの数を得る ABC177,157D参照
};
//

/////main/////
int main()
{
  int clock_on = 0; //提出時は0!!!!!!!!!!!!!!!!!
  int time_clock = clock();
  //
  string S,T;
  cin>>S>>T;
  rep(0,i,S.size()-1){
   if(S.at(i)!=S.at(i)) {cout<<"No"<<endl;return 0;}
  }
cout<<"Yes"<<endl;

  //
  if (clock_on == 1)
    printf("Execution Time: %.4lf sec\n", 1.0 * (clock() - time_clock) / CLOCKS_PER_SEC);
  return 0;
}
/////main/////

/////function/////
//階乗を出力する
ll facctorialMethod(ll k)
{
  ll sum = 1;
  for (ll i = 1; i <= k; ++i)
  {
    sum *= i;
  }
  return sum;
}

// a^n mod を計算する
ll modpow(ll a, ll n, ll mod)
{
  ll res = 1;
  while (n > 0)
  {
    if (n & 1)
      res = res * a % mod;
    a = a * a % mod;
    n >>= 1;
  }
  return res;
}

//最大公約数
ll gcd(ll a, ll b)
{
  if (a % b == 0)
  {
    return b;
  }
  else
  {
    return gcd(b, a % b);
  }
}

//最小公倍数
ll lcm(ll a, ll b)
{
  return a * b / gcd(a, b);
}

//１次元配列の最大値を返すO(NlogN)
ll vecmax(vector<ll> v)
{
  sor(v);
  return v.at(v.size() - 1);
}

//１次元配列の最小値を返すO(NlogN)
ll vecmin(vector<ll> v)
{
  sor(v);
  return v.at(0);
}