use proconio::{input, marker::Chars};

fn main() {
    input! {
        n: usize,
        s: Chars,
    }

    let mut count_white = 0;
    for &c in s.iter() {
        if c == '.' {
            count_white += 1;
        }
    }

    let mut count_black = 0;
    let mut ans = n;

    for c in s {
        match c {
            '.' => count_white -= 1,
            '#' => count_black += 1,
            _ => {}
        }
        ans = std::cmp::min(ans, count_black + count_white);
    }

    println!("{}", ans);
}


use proconio::{input, marker::Chars};

fn main() {
    input! {
        n: usize,
        s: Chars,
    }

    let mut count_white = vec![];
    let mut count_black = vec![];
    for &c in s.iter() {
        let a = if c == '#' { 1 } else { 0 };
        if let Some(&last) = count_black.last() {
            count_black.push(last + a);
        } else {
            count_black.push(a);
        }
    }
    for &c in s.iter() {
        let a = if c == '.' { 1 } else { 0 };
        if let Some(&last) = count_white.last() {
            count_white.push(last + a);
        } else {
            count_white.push(a);
        }
    }
    count_white.reverse();

    let mut ans = n;
    for i in 0..=n {
        let mut temp = 0;
        if i > 0 {
            temp += count_black[i - 1];
        }
        if i < n {
            temp += count_white[i];
        }

        ans = std::cmp::min(ans, temp);
    }

    println!("{}", ans);
}


// -*- coding:utf-8-unix -*-

use std::cmp::*;
use std::collections::*;
use std::fs::File;
use std::io::prelude::*;
use std::io::*;
use std::vec;

const INF: i64 = 1223372036854775807;
const MEM_SIZE: usize = 202020;

use std::cmp::*;
use std::collections::*;
use std::io::stdin;
use std::io::stdout;
use std::io::Write;
#[allow(dead_code)]
fn read<T: std::str::FromStr>() -> T {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).ok();
    s.trim().parse().ok().unwrap()
}
#[allow(dead_code)]
fn read_vec<T: std::str::FromStr>() -> Vec<T> {
    read::<String>()
        .split_whitespace()
        .map(|e| e.parse().ok().unwrap())
        .collect()
}
#[allow(dead_code)]
fn read_vec2<T: std::str::FromStr>(n: u32) -> Vec<Vec<T>> {
    (0..n).map(|_| read_vec()).collect()
}

#[allow(unused_macros)]
macro_rules! p {
    ([$($x:expr), *]) => {{
        let mut f = true;
        $(
            print!("{}{}", if f {""} else {" "}, $x);
            f = false;
        )*
78786    print!("\n");
    }};
    ($x:expr) => {{
        let mut f = true;
        for a in $x.iter() {
            print!("{}{}", if f {""} else {" "}, a);
            f = false;
        }
        print!("\n");
    }};
}
#[allow(dead_code)]
fn readii() -> (i64, i64) {
    let mut str = String::new();
    let _ = stdin().read_line(&mut str).unwrap();
    let mut iter = str.split_whitespace();
    (
        iter.next().unwrap().parse::<i64>().unwrap(),
        iter.next().unwrap().parse::<i64>().unwrap(),
    )
}
#[allow(dead_code)]
fn readuu() -> (usize, usize) {
    let mut str = String::new();
    let _ = stdin().read_line(&mut str).unwrap();
    let mut iter = str.split_whitespace();
    (
        iter.next().unwrap().parse::<usize>().unwrap(),
        iter.next().unwrap().parse::<usize>().unwrap(),
    )
}

#[allow(dead_code)]
fn vector_accumulation(vec: &Vec<i64>) -> Vec<i64> {
    let mut res = Vec::new();
    let size = vec.len();
    res.push(0);
    for i in 0..size {
        res.push(vec[i]);
    }
    for i in 0..size {
        res[i + 1] += res[i];
    }
    res
}

fn solve() {
    let n: usize = read();
    let s: String = read();
    let mut v = s.as_bytes().to_vec();
    let mut vec: Vec<i64> = vec![0; n];
    for i in 0..n {
        if v[i] == '#' as u8 {
            vec[i] = 1;
        }
    }

    let avec = vector_accumulation(&vec);
    let mut res = INF;
    for i in 0..(n + 1) {
        let b = avec[i];
        let w = n as i64 - avec[i];
        res = min(res, ((n - i) as i64 - b).abs() + ((n) as i64 - w).abs());
    }
    println!("{}", res);

    return;
}
fn main() {
    solve()
}


readLine()
let S=readLine()!.characters.map{$0>"#" ?1:0}
var i=S.reduce(0){$0+$1}
print(S.reduce(i){min($0,$1>0 ? --i:++i)})


let N = Int(readLine()!)!
let S = readLine()!.characters.map{$0>"#" ?1:-1}
var cnt = S.filter{$0>0}.count
var ans = cnt
for i in S {
    cnt -= i
    ans = min(cnt, ans)
}
print(ans)


let N = Int(readLine()!)!
let S = readLine()!.characters.map{$0>"#" ?1:0}
var cnt = S.reduce(0){$0+$1}
print(S.reduce(cnt){min($1>0 ? --cnt:++cnt, $0)})


let num = Int(readLine()!)
let str = readLine()!

var prevs: String = ""
var bcount: Int = 0
var wcount: Int = 0
var count = 1

for s in str.characters {
    if( ( String(s) == "." ) ) {
      wcount += 1
    }

  	if( String(s) == "#" ) && ( count != num )  {
      bcount += 1
    }

  	prevs = String(s)
  	count += 1
}

if( bcount < wcount ) {
  print( bcount  )
} else {
  print( wcount  )
}


let num = Int(readLine()!)
let str = readLine()!

var prevs: String = ""
var bcount: Int = 0
var wcount: Int = 0

for s in str.characters {
    if( ( String(s) == "." ) && ( prevs == "#" ) ) {
      bcount += 1
    }

  	if( String(s) == "." ) {
      wcount += 1
    }

  	prevs = String(s)
}

if( bcount < wcount ) {
  print( bcount )
} else {
  print( wcount )
}


let num = Int(readLine()!)
let str = readLine()!

var prevs: String = ""
var bcount: Int = 0
var wcount: Int = 0

for s in str.characters {
    if( ( String(s) == "#" ) && prevs = "." ) {
      bcount += 1
    }

  	if( String(s) == "." ) {
      wcount += 1
    }

  	prevs = String(s)
}

if( bcount < wcount ) {
  print( bcount )
} else {
  print( wcount )
}


const solve = (s) => {
  let w = []
  let wc = 0
  let b = []
  let bc = 0
  s.split("").map((c, i) => {
    if (c == ".") {
      wc++
    } else {
      bc++
    }
    w[i] = wc
    b[i] = bc
  })
  let r = []
  let res = s.length
  for (var i = 0; i < w.length; i++) {
    let bb = b[i - 1] || 0
    let ww = w[w.length - 1] - w[i]
    let rr = bb + ww
    res = Math.min(res, rr)
  }
  return res
}
const main = (input) => {
  const [n, s] = input.split("\n")
  return solve(s)
}

if (process.env.NODE_ENV !== "test") {
  const input = require("fs").readFileSync("/dev/stdin", "utf8")
  console.log(main(input.trim()))
}


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

const N = Number(stdin.split('\n')[0])
const s = stdin.split('\n')[1]

const S = s.split('')

let leftBlack = 0
let rightWhite = S.reduce((p, c) => {
  return p += c === '.' ? 1 : 0
}, 0)

let min = Math.min(rightWhite, N - rightWhite)
S.forEach(v => {
  leftBlack += v === '#' ? 1 : 0
  rightWhite -= v === '.' ? 1 : 0

  const sum = leftBlack + rightWhite

  min = sum < min ? sum : min
})

console.log(min)


const p = (...args) => {
  process.env.NODE_ENV === "test" ? console.log(...args) : ""
}

const solve1 = (s) => {
  let b = false
  let cnt = 0
  s.split("").map((c) => {
    if (c == "#" && !b) {
      b = true
    }
    if (c == "." && b) {
      cnt++
    }
  })
  return cnt
}
const solve2 = (s) => {
  let b = false
  let cnt = 0
  s.split("")
    .reverse()
    .map((c) => {
      if (c == "." && !b) {
        b = true
      }
      if (c == "#" && b) {
        cnt++
      }
    })
  return cnt
}

const main = (input) => {
  const [n, s] = input.split("\n")

  return Math.min(solve1(s || ""), solve2(s || ""))
}

if (process.env.NODE_ENV !== "test") {
  const input = require("fs").readFileSync("/dev/stdin", "utf8")
  console.log(main(input.trim()))
}


const p = (...args) => {
  process.env.NODE_ENV === "test" ? console.log(...args) : ""
}

const solve = (s) => {
  let b = false
  let cnt = 0
  s.split("").map((c) => {
    if (c == "#" && !b) {
      b = true
    }
    if (c == "." && b) {
      cnt++
    }
  })
  return cnt
}
const main = (input) => {
  const [n, s] = input.split("\n")

  return solve(s || "")
}

if (process.env.NODE_ENV !== "test") {
  const input = require("fs").readFileSync("/dev/stdin", "utf8")
  console.log(main(input.trim()))
}


const solve = (s) => {
  let b = false
  let cnt = 0
  s.split("").map((c) => {
    if (c == "#" && !b) {
      b = true
    }
    if (c == "." && b) {
      cnt++
    }
  })
  return cnt
}
const main = (input) => {
  const [n, s] = input.split("\n")

  return solve(s)
}

if (process.env.NODE_ENV !== "test") {
  const input = require("fs").readFileSync("/dev/stdin", "utf8")
  console.log(main(input.trim()))
}


h, a = map(int,input().split())

if h % a == 0:
    print(h//a)
else:
    print(h//a + 1)


H, A = map(int, input().split())
if H % A == 0:
  ans = H // A
else:
  ans = H // A + 1
print(ans)


import sys

for line in sys.stdin:
    h, a = list(map(lambda x: int(x), line.split()))
    hits = h // a
    if h % a == 0 and a > 0:
        print(hits)
    else:
    	print(hits + 1)


h, a = map(int, input().split())

print(h//a + 1)


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

ans=(H+N)//N
print(ans)


h,a = map(int,input().split())

if h % a == 0:
  print(h / a)
else :
  print(h // a + 1)


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));

		String parts[] = br.readLine().split(" ");

		int H = Integer.parseInt(parts[0]);
		int A = Integer.parseInt(parts[1]);

		int a = H%A;

		if(a==0) {
			System.out.println(H/A);
		}else {
			System.out.println(H/A+1);
		}

	}

}


/*
    Those who cannot remember the past are condemned to repeat it.
                                            - Dynamic Programming

    I never lose, I either win or I learn.
                - Competitive Programming

*/

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

public class Main {
    public static void main(String[] args) throws Exception {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st;
        PrintWriter pw = new PrintWriter(System.out);

        st = new StringTokenizer(br.readLine());
        int n = Integer.parseInt(st.nextToken());
        int k = Integer.parseInt(st.nextToken());
        int ans = 0;
        if(n%k == 0) {
            ans = n/k;
        }
        else {
            ans = n/k+1;
        }

        pw.println(ans);

        pw.flush();
        pw.close();
    }
}


import java.io.*;
import java.util.*;
import static java.lang.System.*;
import static java.lang.Math.*;

public class Main
{
	public static void main(String []args)throws IOException
	{
		BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
		String []s=br.readLine().split(" ");
		int H = Integer.parseInt(s[0]);
		int A = Integer.parseInt(s[1]);

		if(H%A!=0)
			out.println((H/A)+1);
		else
			out.println((H/A));

	}
}


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

public class Main {

    public static void main(String[] args) throws IOException {
        Scanner s = new Scanner(System.in);
        int h = s.nextInt(),a = s.nextInt();
        System.out.println((int)(Math.ceil(h/a)));

    }
}

class Scanner
{
    StringTokenizer st;
    BufferedReader br;

    public Scanner(InputStream s){	br = new BufferedReader(new InputStreamReader(s));}

    public String next() throws IOException
    {
        while (st == null || !st.hasMoreTokens())
            st = new StringTokenizer(br.readLine());
        return st.nextToken();
    }

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

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

    public String nextLine() throws IOException {return br.readLine();}

    public double nextDouble() throws IOException
    {
        String x = next();
        StringBuilder sb = new StringBuilder("0");
        double res = 0, f = 1;
        boolean dec = false, neg = false;
        int start = 0;
        if(x.charAt(0) == '-')
        {
            neg = true;
            start++;
        }
        for(int i = start; i < x.length(); i++)
            if(x.charAt(i) == '.')
            {
                res = Long.parseLong(sb.toString());
                sb = new StringBuilder("0");
                dec = true;
            }
            else
            {
                sb.append(x.charAt(i));
                if(dec)
                    f *= 10;
            }
        res += Long.parseLong(sb.toString()) / f;
        return res * (neg?-1:1);
    }

    public boolean ready() throws IOException {return br.ready();}

}


import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
Scanner SC = new Scanner(System.in);
int H = SC.nextInt();
int A = SC.nextInt();
System.out.println(H + A - 1/A);
	}

}


/*
 * Click `Run` to execute the snippet below!
 */

import java.io.*;
import java.util.*;

/*
 * To execute Java, please define "static void main" on a class
 * named Solution.
 *
 * If you need more classes, simply define them inline.
 */

public class Main {

  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int H = sc.nextInt();
    int A = sc.nextInt();
    System.out.println(Math.ceil(1.0 * H / A));
  }
}


#include<stdio.h>
int main(){
    int h;
    int a;
    scanf("%d",&h);
    scanf("%d",&a);
    if(h%a==0){
        printf("%d",h/a);
    }else{
        printf("%d",h/a+1);
    }
    return 0;
}


#include <stdio.h>

int h,a;

int main()
{
    scanf("%d%d",&h,&a);
    printf("%d\n",h%a==0?h/a:h/a+1);
}


#include <stdio.h>
int main(){
  int H,A,num;
  num = 0;
  scanf("%d",&H);
  scanf("%d",&A);
  while(0<H){
  num++;
  H-=A;
  }
  printf("%d",num);
 	return 0;
}


#include <iostream>
using namespace std;

int main() {
    int H, A,i;
    cin>>H>>A;
    while (H>0){
    H-=A;
    i++;
    }
    cout<<i;

    return 0;
    }


#include <bits/stdc++.h>
#define inf 1000000005
#define mod 1000000007
#define eps 1e-10
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define rrep(i,n) for(int i = 1; i <= (n); ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
#define each(a,b) for(auto& (a): (b))
#define all(v) (v).begin(),(v).end()
#define sz(v) (int)(v).size()
#define zip(v) sort(all(v)),v.erase(unique(all(v)),v.end())
#define mx(x,y) x=max(x,y)
#define mn(x,y) x=min(x,y)
#define rev(v) reverse((v).begin(),(v).end());
#define so(v) sort((v).begin(), (v).end());
#define yn {puts("Yes");}else{puts("No");}
#define fi first
#define se second
#define pb push_back

using namespace std;

using ll = long long;
using P = pair<int,int>;
using pll = pair<ll, ll>;
using vi = vector<int>;
using vvi = vector<vi>;
using vl = vector<ll>;
using vvl = vector<vl>;
using vd = vector<double>;
using vp = vector<P>;
using vs = vector<string>;

int main() {
    int a, b, ct,ans;
    string s;
 	 cin>>s;
    int r;
    a = sz(s);
    b = 0;
    ct = 0;
    rep(i, a) {
        if (s.at(i) == 'W') {
            ct = ct + i + 1-1-b;
            b++;
        }
    }
    cout<<ct<<endl;
    return 0;
}


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

	int A, B, H;

	scanf("%d %d", &A, &B);

	while (A>0){
		A= A - B;
		H++;
	}
	printf("%d\n", H):
 	return 0;
 }


#include <stdio.h>

int main()
{
    int h,a = 0;

    scanf("%d %d",&h,&a);

    if (h - a*(h/a) == 0) printf("%d",h/a);
    else printf("%d",h/a+1);

    return 0;
}


#include<stdio.h>

int main(void){
 	int H,A;

	scanf("%d %d",&H,&A);

 	int i=0;

  	while(H>0){
		    H=H-A;
      	i++;
    }

    printf("%d",i);

  	return 0;
}


#include<stdio.h>
int main(){
  int i,j;//i:モンスターの体力　j:攻撃一回につき減らせる体力
  scanf("%d %d",&i,&j);
  int n=i;
  int t=0;
  while(n>0){
    n-=j;
    t++;
  }
  printf("%d\n",t);
  return 0;
}


#include <stdio.h>

int main(void)
{
    int h=0,a=0,count=0;
    scanf("%d %d",&h,&a);

    while(h<=0){
        h-=a;
        count+=1;
    }
    printf("%d",count);
    return 0;
}


#include <stdio.h>

int main()
{
  int H,A;
  scanf("%d %d", &H, &A);
  int c=a/b;
  if (H%A != 0){
  	c++;
  }

  	printf ("%d\n",c);
  	return 0;
  }


#include <stdio.h>

int main()
{
  int H,A;
  scanf("%d %d", &H, &A);
  if (H%A == 0){
  	printf("%d\n",H/A);
  }
  else
  	printf ("%d\n",(H/A)+1);
  }
  return 0;
}


function main(input) {
    const args = input.split(' ');
    const h = parseInt(args[0]);
    const a = parseInt(args[1]);

	console.log(Math.ceil(h/a));
}

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


"use strict";
// inputに入力データ全体が入る
function Main(input) {
  // 1行目がinput[0], 2行目がinput[1], …に入る
  input = input.split("\n");
  let tmp = input[0].split(" ");
  //文字列から10進数に変換するときはparseIntを使います
  let h = parseInt(tmp[0], 10);
  let a = parseInt(tmp[1], 10);
  //出力
  console.log("%d", Math.ceil((1.0 * h) / a));
}
//*この行以降は編集しないでください（標準入出力から一度に読み込み、Mainを呼び出します）
Main(require("fs").readFileSync("/dev/stdin", "utf8"));


function main(input) {
    input = input.split(" ");
    var h = parseInt(input[0], 10);
    var a = parseInt(input[1], 10);

    console.log(Math.ceil(a/b));
}

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


function main(input) {
    input = input().split(" ");
    var h = parseInt(input[0], 10);
    var a = parseInt(input[1], 10);

    console.log(Math.ceil(a/b));
}

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


function main(input) {
    var input = input().split(" ");
    var h = parseInt(input[0], 10);
    var a = parseInt(input[1], 10);

    console.log(Math.ceil(a/b));
}

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


package main
import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)
func newScanner() *bufio.Scanner{
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Split(bufio.ScanWords)
	return scanner
}

var sc = newScanner()

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

func scanInts(n int) []int{
	a := make([]int, n)
	for i := 0; i < n; i++ {
		a[i] = scanInt()
	}
	return a
}

func scanString() string{
	if sc.Scan() {
		return sc.Text()
	}
	panic(sc.Err())
}

func main() {
	n := scanInt()
	h := scanInt()
	answer := countAttacks(n, h)
	fmt.Println(answer)
}

func countAttacks(n, h int) int {
	if n % h == 0 {
		return n / h
	}
	return n / h + 1
}


package main

import "fmt"

func main(){
	var H, A, ans int;
	fmt.Scan(&H, &A);

	for i := H ; i > 0 ; i-=A {
		ans++;
	}

	fmt.Println(ans);
}


package main

import (
	"fmt"
)

func main() {
	var h, a int
	fmt.Scan(&h, &a)
	at := h / a
	if h%a != 0 {
		at++
	}
	fmt.Println(at)
}


package main

import (
	"fmt"
)

func main() {
	var h, a int
	fmt.Scanf(&h, &a)
	fmt.Println((h + a - 1) / a)
}


package main

import (
	"fmt"
)

func main() {
	var h, a int
	fmt.Scan(&h, &a)

	if h%a == 0 {
		fmt.Println(h/a + 1)
	} else {
		fmt.Println(h / a)
	}
}


package main

import (
	"fmt"
)

func main() {
  var h, a int
  fmt.Scanf("%d %d", &h, &a)
  ans := (h / a) + 1

  fmt.Printf("%d\n", ans)
}


h, a = gets.split.map(&:to_i)

n = (h/a.to_f).ceil
puts n


# H A

h, a = gets.chomp.split(" ").map(&:to_i)

c = h / a

if h % a == 0
else
  c = c + 1
end

puts c


H, A = gets.chomp.split.map(&:to_i)
puts (H / A.to_f).ceil


h, a = gets.split.map(&:to_i)

puts h/a + 1


h,a = gets.chomp.split(" ").map(&:to_i)

h/a == 0 ? h/a : h/a+1


h,a = gets.chomp.split(" ").map(&:to_i)

h/a == 0 ? a/b : a/b+1


use proconio::input;

fn main() {
    input! {
    h: u32,
    a: u32,
    }

    println!("{}", (h + a - 1) / a);
}


macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
        let mut iter = $s.split_whitespace();
        let mut next = || { iter.next().unwrap() };
        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)*}
    };
}

macro_rules! input_inner {
    ($next:expr) => {};
    ($next:expr, ) => {};

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

macro_rules! read_value {
    ($next:expr, ( $($t:tt),* )) => {
        ( $(read_value!($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!{
        h: usize,
        a: usize,
    }

    if h%a==0{
        println!("{}", h/a);
    } else {
        println!("{}", h/a+1);
    }

}


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

fn main() {
	let (h, a): (f32, f32) = (read(), read());
	let ans = (h / a).ceil() as u32;
	println!("{}", ans);
}

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")
}


// unihernandez22
// https://atcoder.jp/contests/abc153/tasks/abc153_a
// math

use std::io::stdin;

fn main() {
    let mut s = String::new();
    stdin().read_line(&mut s).unwrap();

    let words: Vec<i64> = s
        .split_whitespace()
        .map(|x| x.parse().unwrap())
        .collect();

    let h = words[0];
    let a = words[0];

    println!("{}", (h + a-1) / a);
}


use proconio::input;
#[allow(unused_imports)]
use proconio::marker::*;

fn main() {
    input! {
        h : i32, a : i32,
    }
    println!("{}", kyopro_lib::misc::ceil(h, a));
}


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")
}

pub fn read_n<T: FromStr>(n: usize) -> Vec<T> {
    read_n_logic::<T>(n, vec![])
}

pub fn read_n_logic<T: FromStr>(n: usize, mut a: Vec<T>) -> Vec<T> {
    match n {
        0 => a,
        _ => {
            a.push(read::<T>());
            read_n_logic(n - 1, a)
        }
    }
}
use std::cmp::{max, min};

fn main() {
    let n: i64 = read();
    let m: i64 = read();
    println!("{}", n / m +1);
}


extension String:CollectionType{}
func readInts()->[Int]{
  return readLine()!.split(" ").map{Int($0)!}
}
let a:[Int]=readInts()
let n=a[0]
let m=a[1]
let ans=(n+m-1)/m
print(ans)


let arr = readLine()!.characters.split{$0==" "}.map{Int(String($0))}
let h = arr[0]!
let a = arr[1]!
let amari = ( h % a ) > 0 ? 1 : 0
print(h / a + amari)


func readInts() -> [Int] {
    return readLine()!.split(separator: " ").map { Int($0)! }
}

func main() {
    let ha = readInts()
    let h = ha[0]
    let a = ha[1]

    if h % a == 0 {
        print(h / a)
    } else {
        print(h / a + 1)
    }
}

main()


let input = readLine()!.split(separator: " ").map { Int($0)! }
let H = input[0]
let A = input[1]

var times = H / A
if H - H / A > 0 {
  times += 1
}
print(times)


let a = readLine()!.split(separator: " ").map({Int($0)})

let H = a[0]!
let A = a[1]!

var count = 1
while H >= A * count {
    count += 1
}
print(count)


 if let  str = readLine() {
    let arr = str.split(separator: " ").map { Int($0)}
    if let H = arr[0], let A = arr[1] {
        print(H % A == 0 ? (H / A) : (H / A + 1))
    }
 }


import * as fs from "fs";

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

//const [n, m] = input[0].split(" ").map((x: string): number => +x);
//const a = input[1].split(" ").map((x: string): number => +x);

const [h, a] = input[0].split(' ').map((x: string): number => +x);

if(h % a === 0){
	console.log(Math.floor(h/a));
}else{
	console.log(Math.floor(h/a) + 1);
}


import { readFileSync } from "fs";
const input = readFileSync("/dev/stdin", "utf8");

let [H, N] = input.split(" ").map(s => ~~s);

let count = 0;

while (H > 0) {
    H = H - N;
    count = count + 1;
}

console.log(count);


import * as fs from 'fs';

const input = fs.readFileSync('/dev/stdin', 'utf8').split(/[ \n]/);
const h = +input[0];
const a = +input[1];

console.log(Math.ceil(h / a));


export class HeroDetailService {

    constructor() { }
    CalcAttackTimes(HP: number , Attack: number): number {
       let CountTimes: number;
      CountTimes = 0;
      for(;HP > 0; this.JudgeWinLose(HP) == false){
        HP = this.CalcHp(HP,Attack);
        CountTimes++;
       }
       return CountTimes;
      }

    CalcHp(HP: number , Attack: number): number {
      return HP - Attack;
    }

    JudgeWinLose(HP: number): boolean {
      if(HP <= 0 ){
        return false;
      }
      else if(HP > 0){
        return true;
      }
    }
}


const main = arg => {
  const [H, A] = arg.trim().split(' ');
  console.log(parseInt(H / A) + 1);
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));


const main = arg => {
  const [H, A] = arg.trim().split(' ');
  console.log(parseInt(H / A));
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));


n=input()
lst=input().split()
if len(lst)==len(set(lst)):
    print("YES")
else: print("NO")


n = int(input())
num = input().split()

if len(set(num)) == n:
  print("YES")
else:
  print("NO")


N = input()
A = input().split()
n = len(A)
n_temp = len(set(A))

if n != n_temp:
  print("NO")
else:
  print("YES")


n=int(input())
a = list(map(int,input().split()))
for i in range (n):
  for j in range(n):
    if i != j:
      if a[i] == a[j]:
        print('NO')
        exit()
print('YES')


N = int(input())
nums = set(map(int, input().split()))

if len(nums) == N:
  print("Yes")
else:
  print("No")


n = int(input())
a = list(map(int, input().split()))

for i in range(n):
    if a.count(a[i]) == 1:
        continue
    else:
        print('NO')
        exit()

print('YES')


import java.io.*;
import java.util.*;
import java.math.*;
// import java.awt.Point;

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

    static int mod = 1_000_000_007;
    // int mod = 998244353;
    // long inf = Long.MAX_VALUE/2;
    int inf = Integer.MAX_VALUE/2;

    void solve(){
        int n = ni();
        int[] a = new int[n];
        for(int i = 0; i < n; i++){
            a[i] = ni();
        }
        Arrays.sort(a);
        for(int i = 1; i < n; i++){
            if(a[i]==a[i-1]){
                out.println("NO");
                return;
            }
        }
        out.println("YES");
    }

    void run() throws Exception
    {
        is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes());
        out = new PrintWriter(System.out);
        long s = System.currentTimeMillis();
        solve();
        out.flush();
        if(!INPUT.isEmpty())tr(System.currentTimeMillis()-s+"ms");
    }

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

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

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

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

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

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

    private 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 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) { System.out.println(Arrays.deepToString(o)); }

}


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

public class Main {

	public static void main(String[] args) {
		FastScanner sc = new FastScanner();
		int N = sc.nextInt();
		int[] A = new int[N];
		for (int i = 0; i < N; i++)
			A[i] = sc.nextInt();

		Arrays.sort(A);
		for (int i = 1; i < N; i++) {
			if (A[i] == A[i - 1]) {
				System.out.println("NO");
				return;
			}
		}
		System.out.println("YES");

	}

	//以下、自作ライブラリ

	/*
		int N = sc.nextInt();

		int[] a = new int[N];
		for (int i = 0; i < N; i++)
			a[i] = sc.nextInt();

		String s = sc.next();

		String[] a = new String[N];
		for (int i = 0; i < N; i++)
			a[i] = sc.next();

		int[][] a = new int[N][2];
		for (int i = 0; i < N; i++) {
			a[i][0] = sc.nextInt();
			a[i][1] = sc.nextInt();
		}
		Arrays.sort(a, (x, y) -> Integer.compare(x[0], y[0]));

		List<Integer> list = new ArrayList<>();

		Set<Integer> set = new HashSet<>();

		Map<Integer, Integer> map = new HashMap<>();

		nextLineのときは
		Scanner sc = new Scanner(System.in);
	 */

	//階乗
	public static int fact(int n) {
		if (n == 1 || n == 0)
			return 1;
		else
			return n * fact(n - 1);
	}

	//指定した値以上の要素が最初に現れる位置
	//要素の数は+1（配列のズレ)
	public static long lowerBound(int n, long[] x, long y) {
		int left = 0;
		int right = n;
		while (left < right) {
			int mid = (left + right) / 2;
			if (x[mid] < y) {
				left = mid + 1;
			} else {
				right = mid;
			}
		}
		return left;
	}

	//指定した値より大きい要素が最初に現れる位置
	//要素の数は+1（配列のズレ)
	public static long upperBound(int n, long[] x, long y) {
		int left = 0;
		int right = n;
		while (left < right) {
			int mid = (left + right) / 2;
			if (x[mid] <= y) {
				left = mid + 1;
			} else {
				right = mid;
			}
		}
		return left;
	}

	//最大公約数
	public static long gcd(long a, long b) {
		if (a < b)
			return gcd(b, a);
		long c = 0;
		c = a % b;
		if (c == 0)
			return b;
		return gcd(b, c);
	}

	//最小公倍数
	public static long lcm(long m, long n) {
		return m * n / gcd(m, n);
	}

	//素数判定
	public static boolean isPrime(int n) {
		if (n < 2)
			return false;
		if (n == 2)
			return true;
		if (n % 2 == 0)
			return false;

		for (int i = 3; i * i <= n; i += 2) {
			if (n % i == 0)
				return false;
		}
		return true;
	}
}

//以下、高速スキャナークラス
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.*;
import java.io.*;

public class Main {

    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        OutputWriter out = new OutputWriter(outputStream);
        Solve solver = new Solve();
        solver.solve(1, in, out);
        out.close();
    }

    static class Solve {
    	public void solve(int testNumber, InputReader in, OutputWriter out) {
    		int n = in.nextInt();
    		Set<Integer> p = new HashSet<Integer>();
    		for(int i = 0;i<n;i++)p.add(in.nextInt());
    		if(p.size()==n)out.println("YES");
    		else out.println("NO");
    	}
    }

    static class OutputWriter {
	    private final PrintWriter writer;

	    public OutputWriter(OutputStream outputStream) {
	        writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
	    }

	    public OutputWriter(Writer writer) {
	        this.writer = new PrintWriter(writer);
	    }

	    public void close() {
	        writer.close();
	    }

	    public void println(String string) {
	        writer.println(string);
	    }

	    public void println(char string) {
	        writer.println(string);
	    }

	    public void println(int number) {
	        writer.println(number);
	    }

	    public void println(long number) {
	        writer.println(number);
	    }

	    public void println(double number) {
	    	writer.println(number);
	    }

	    public void print(long number) {
	        writer.print(number);
	    }

	    public void print(int number) {
	        writer.print(number);
	    }

	    public void print(char string) {
	        writer.print(string);
	    }

	    public void print(String string) {
	        writer.print(string);
	    }

	    public void print(double number) {
	    	writer.print(number);
	    }
	}

	static class InputReader {
		private InputStream in;
		private byte[] buffer = new byte[1024];
		private int curbuf;
		private int lenbuf;

		public InputReader(InputStream in) {
			this.in = in;
			this.curbuf = this.lenbuf = 0;
		}

		public String nextLine() {
			StringBuilder sb = new StringBuilder();
			int b = readByte();
			while (b!=10) {
				sb.appendCodePoint(b);
				b = readByte();
			}
			if(sb.length()==0)return "";
			return sb.toString().substring(0,sb.length()-1);
		}

		public boolean hasNextByte() {
			if (curbuf >= lenbuf) {
				curbuf = 0;
				try {
					lenbuf = in.read(buffer);
				} catch (IOException e) {
					throw new InputMismatchException();
				}
				if (lenbuf <= 0)
					return false;
			}
			return true;
		}

		private int readByte() {
			if (hasNextByte())
				return buffer[curbuf++];
			else
				return -1;
		}

		private boolean isSpaceChar(int c) {
			return !(c >= 33 && c <= 126);
		}

		private void skip() {
			while (hasNextByte() && isSpaceChar(buffer[curbuf]))
				curbuf++;
		}

		public boolean hasNext() {
			skip();
			return hasNextByte();
		}

		public String next() {
			if (!hasNext())
				throw new NoSuchElementException();
			StringBuilder sb = new StringBuilder();
			int b = readByte();
			while (!isSpaceChar(b)) {
				sb.appendCodePoint(b);
				b = readByte();
			}
			return sb.toString();
		}

		public int nextInt() {
			if (!hasNext())
				throw new NoSuchElementException();
			int c = readByte();
			while (isSpaceChar(c))
				c = readByte();
			boolean minus = false;
			if (c == '-') {
				minus = true;
				c = readByte();
			}
			int res = 0;
			do {
				if (c < '0' || c > '9')
					throw new InputMismatchException();
				res = res * 10 + c - '0';
				c = readByte();
			} while (!isSpaceChar(c));
			return (minus) ? -res : res;
		}

		public long nextLong() {
			if (!hasNext())
				throw new NoSuchElementException();
			int c = readByte();
			while (isSpaceChar(c))
				c = readByte();
			boolean minus = false;
			if (c == '-') {
				minus = true;
				c = readByte();
			}
			long res = 0;
			do {
				if (c < '0' || c > '9')
					throw new InputMismatchException();
				res = res * 10 + c - '0';
				c = readByte();
			} while (!isSpaceChar(c));
			return (minus) ? -res : res;
		}

		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 char[][] nextCharMap(int n, int m) {
			char[][] map = new char[n][m];
			for (int i = 0; i < n; i++)
				map[i] = next().toCharArray();
			return map;
		}
	}
}


import java.util.*;

public class Main {
    public static void main(String args[]) {
        Scanner scn = new Scanner(System.in);
        int n = scn.nextInt();
        ArrayList<String> intList = new ArrayList<String>();

        for(int i=0;i<n;i++){
            intList.add(scn.next());
        }

        Set<String> intSet = new HashSet<String>(intList);

        if(n==intSet.size()){
            System.out.println("Yes");
        }else{
            System.out.println("No");
        }

        scn.close();

    }

}


import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int now = 0;
        ArrayList<Integer> c = new ArrayList<Integer>();
        for (int i = 0; i < n; i++) {
            now = sc.nextInt();
            if (c.contains(now)) {
                System.out.println("NO");
                System.exit(0);
            } else {
                c.add(now);
            }
        }
        System.out.println("YES");
    }
}


import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        Integer[] a = new Integer[n];
        for(int i = 0; i < n; i++) {
            a[i] = sc.nextInt();
        }
        Arrays.sort(a);
        ArrayList<Integer> c = new ArrayList<Integer>();
        for(int i = 0; i < n; i++) {
            if(c.contains(a[i])) {
                System.out.println("NO");
                System.exit(0);
            }else{
                c.add(a[i]);
            }
        }
        System.out.println("YES");
    }
}


#pragma GCC optimize ("O3")
#pragma GCC target ("avx")
//#include<bits/stdc++.h>
#include<cstdio>
using namespace std;
typedef long long ll;
#define rep(i, n) for(int i = 0; i < (n); i++)
#define rep1(i, n) for(int i = 1; i <= (n); i++)
#define co(x) cout << (x) << "\n"
#define cosp(x) cout << (x) << " "
#define ce(x) cerr << (x) << "\n"
#define cesp(x) cerr << (x) << " "
#define pb push_back
#define mp make_pair
#define chmin(x, y) x = min(x, y)
#define chmax(x, y) x = max(x, y)
#define Would
#define you
#define please

const int cm = 1 << 17;
char cn[cm], * ci = cn + cm, ct;
inline char getcha() {
	if (ci - cn == cm) { fread_unlocked(cn, 1, cm, stdin); ci = cn; }
	return *ci++;
}
inline int getint() {
	int A = 0;
	if (ci - cn + 16 > cm) while ((ct = getcha()) >= '0') A = A * 10 + ct - '0';
	else while ((ct = *ci++) >= '0') A = A * 10 + ct - '0';
	return A;
}

void pakuri_sort(int N, int A[]) {
	const int b = 8;
	int tmp[200001];
	rep(k, 4) {
		int kazu[1 << b] = {}, kazu2[1 << b] = {};
		rep(i, N) kazu[A[i] >> k * b & ((1 << b) - 1)]++;
		rep(i, (1 << b) - 1) kazu[i + 1] += kazu[i];
		for (int i = N - 1; i >= 0; i--) tmp[--kazu[A[i] >> k * b & ((1 << b) - 1)]] = A[i];
		k++;
		rep(i, N) kazu2[tmp[i] >> k * b & ((1 << b) - 1)]++;
		rep(i, (1 << b) - 1) kazu2[i + 1] += kazu2[i];
		for (int i = N - 1; i >= 0; i--) A[--kazu2[tmp[i] >> k * b & ((1 << b) - 1)]] = tmp[i];
	}
}

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

	int N = getint();
	int A[200001];
	rep(i, N) A[i] = getint();
	pakuri_sort(N, A);

	bool OK = 1;
	rep(i, N - 1) OK &= (A[i] != A[i + 1]);

	printf(OK ? "YES" : "NO");

	Would you please return 0;
}


/*                         _
                        _ooOoo_
                       o8888888o
                       88" . "88
                       (| -_- |)
                       O\  =  /O
                    ____/`---'\____
                  .'  \\|     |//  `.
                 /  \\|||  :  |||//  \
                /  _||||| -:- |||||_  \
                |   | \\\  -  /'| |   |
                | \_|  `\`---'//  |_/ |
                \  .-\__ `-. -'__/-.  /
              ___`. .'  /--.--\  `. .'___
           ."" '<  `.___\_<|>_/___.' _> \"".
          | | :  `- \`. ;`. _/; .'/ /  .' ; |
          \  \ `-.   \_\_`. _.'_/_/  -' _.' /
===========`-.`___`-.__\ \___  /__.-'_.'_.-'================

                  Please give me AC.
*/

#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <numeric>
#include <string>
#include <sstream>
#include <complex>
#include <bitset>
#include <vector>
#include <list>
#include <set>
#include <map>
#include <queue>
#include <deque>
#include <stack>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <chrono>
#include <random>

using namespace std;

using int64 = long long;
using uint64 = unsigned long long;
using vi = vector<int>;
using vl = vector<int64>;
using pii = pair<int, int>;
using pll = pair<int64, int64>;

#define rep(i, n) for (int i = 0; i < (int)(n); ++i)
#define all(v) (v).begin(), (v).end()
#define print(x) cout << (x) << '\n'
#define print2(x, y) cout << (x) << ' ' << (y) << '\n'
#define print3(x, y, z) cout << (x) << ' ' << (y) << ' ' << (z) << '\n'
#define printn(v) rep(i, (v).size() - 1) cout << (v)[i] << ' '; cout << (v)[n - 1] << '\n';
#define debug(x) cerr << #x << ": " << (x) << '\n'
#define debug2(x, y) cerr << #x << ": " << (x) << ", " << #y << ": " << (y) << '\n'
#define debug3(x, y, z) cerr << #x << ": " << (x) << ", " << #y << ": " << (y) << ", " << #z << ": " << (z) << '\n'
#define dbg(v) for (size_t _ = 0; _ < v.size(); ++_){cerr << #v << "[" << _ << "] : " << v[_] << '\n';}
// constant
const int INF = (1<<30) - 1;
const int64 INF64 = (1LL<<62) - 1;

template<typename T> T gcd(T a, T b) {
    if (a < b) return gcd(b, a);
    T r;
    while ((r = a % b)) {
        a = b;
        b = r;
    }
    return b;
}

template<typename T> T lcm(const T a, const T b) {
    return a / gcd(a, b) * b;
}

template<typename T> bool chmin(T& a, const T& b) {
    if (a > b) return a = b, true; else return false;
}

template<typename T> bool chmax(T& a, const T& b) {
    if (a < b) return a = b, true; else return false;
}

// End of template.
// begin fast io

char buf[10000000];
int bufi = 0;

template<typename T>
void readui(T &n) {
    n = 0;
    int c = buf[bufi++];
    for (; '0' <= c && c <= '9'; c = buf[bufi++])
        n = 10 * n + c - '0';
}

template<typename T>
void readi(T &n) {
    bool negative = false;
    if (buf[bufi] == '-') negative = true, bufi++;
    readui(n);
    if (negative) n = -n;
}

template<typename T>
void readuf(T &x) {
    x = 0;
    T y = 0;
    int z = 0;
    int c = buf[bufi++];
    for (; '0' <= c && c <= '9'; c = buf[bufi++])
        x = 10 * x + c - '0';
    if (buf[bufi - 1] == '.')
        for (; '0' <= c && c <= '9'; c = buf[bufi++], ++z)
            y = 10 * y + c - '0';
    x += y / pow(10, z);
}

template<typename T>
void readf(T &x) {
    bool negative = false;
    if (buf[bufi] == '-') negative = true, bufi++;
    readuf(x);
    if (negative) x = -x;
}

void reads(string &s) {
    const int begin = bufi;
    int c;
    while (c = buf[bufi++], c != ' ' && c != '\n') {}
    s = string(buf + begin, buf + bufi);
}

void readline(string &s) {
    const int begin = bufi;
    while (buf[bufi++] != '\n') {}
    s = string(buf + begin, buf + bufi);
}

// end fast io

template< typename T, int b = 8, int bit = sizeof(T) * 8> void radix_sort(T* a, int n) {
    T temp[200200];
    T *dist = temp, *src = a;
    constexpr T mask = (1 << b) - 1;
    constexpr int kn = (bit + b - 1) / b;
    for (int k = 0; k < kn; ++k) {
        T bucket[1 << b] = {};
        T index[1 << b];
        for (int i = 0; i < n; ++i) bucket[mask & (src[i] >> (b*k))] += 1;
        index[0] = 0;
        for (int i = 0; i < (1 << b) - 1; ++i) index[i + 1] = index[i] + bucket[i];
        for (int i = 0; i < n; ++i) dist[index[mask & (src[i] >> (b*k))]++] = src[i];
        swap(dist, src);
    }
    if (kn % 2 == 1) {
        memcpy(a, src, sizeof(T) * n);
    }
}

int main() {
    cout << fixed << setprecision(15);
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cin.read(buf, sizeof buf); // 注意: ./a.out < in か pbp | ./a.out で入力すること

    int n, a[200200];
    readui(n);
    rep(i, n) readui(a[i]);
    radix_sort(a, n);
    bool ans = false;
    rep(i, n - 1) ans |= a[i] == a[i + 1];
    if (!ans) print("YES"); else print("NO");

    return 0;
}


#include<bits/stdc++.h>
using namespace std;
using ll=long long;
#define fr(i,n) for(int i=0;i<(n);++i)
#define Fr(i,n) for(int i=1;i<=(n);++i)
#define ifr(i,n) for(int i=(n)-1;i>=0;--i)
#define iFr(i,n) for(int i=(n);i>0;--i)

int HM[358623],*END=HM+358621;

bool insert(int a){
    int *p=HM+a%358621;
    while(*p){
        if(*p==a) return true;
        if(++p==END) p=HM;
    }
    *p=a;
    return false;
}

int main(){
    int n{},a,c;
    while((c=getchar_unlocked()-'0')>=0) n*=10,n+=c;
    fr(i,n){
        a=0;
        while((c=getchar_unlocked()-'0')>=0) a*=10,a+=c;
        if(insert(a)){
            putchar_unlocked('N');
            putchar_unlocked('O');
            putchar_unlocked('\n');
            return 0;
        }
    }
    putchar_unlocked('Y');
    putchar_unlocked('E');
    putchar_unlocked('S');
    putchar_unlocked('\n');
}


#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define fastio ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define gcd(a,b) __gcd((a),(b))
#define lcm(a,b) ((a)*(b))/gcd((a),(b))
const int maxn = 1e9 + 5;
#define INF 1000000000
const int MOD = 1e9+7;
const double PI = 3.14159265358979323846264338;

int main() {
#ifndef ONLINE_JUDGE
	freopen("input.txt", "r", stdin);
	freopen("output.txt", "w", stdout);
#endif
	fastio
    int n;
    cin >> n;
    int a[n];
    set<int> s;
    for(int i=0; i<n; i++){
    	cin >> a[i];
    	s.insert(a[i]);
    }
    if(s.size() == n){
    	cout << "Yes\n";
    }else{
    	cout << "No\n";
    }
    return 0;
}


#include<iostream>
#include<algorithm>
#include<string>
#include<cmath>
#include<vector>
#include<map>
using namespace std;
/*
time:
wa:
反省:
考察:
*/
int main() {
    int n;
    cin >> n;
    int a[200001];
    for(int i = 0; i < n; i++) cin >> a[i];

    for(int i = 0; i < n; i++){
        for(int j = i+1; j < n; j++){
            if(a[i] == a[j]) {
                cout << "NO" << endl;
                return 0;
            }
        }
    }
    cout << "YES" << endl;
    return 0;
}


#include <iostream>
#include <algorithm>
#include<string.h>
using namespace std;
int a[200005];
int main()
{
    int n;
    cin>>n;
    int book[n+5];
    memset(a,0,sizeof(a));
    memset(book,0,sizeof(book));
    for(int i=0; i<n; i++)
    {
        cin>>a[i];
        book[a[i]]++;
    }
    int flag=1;
    for(int i=0; i<n; i++)
    {
       /// cout<<a[i]<<" *"<<endl;
       /// cout <<book[a[i]]<<endl;
        if(book[a[i]]>1)
        {
            flag=0;
            break;
        }
    }
    if(flag)
        cout <<"YES"<< endl;
    else
        cout<<"NO"<<endl;

    return 0;
}


// ABC 154-C
// 2020.2.9 bal4u

#include <stdio.h>

#define gc() getchar_unlocked()

int in() {   // 非負整数の入力
	int n = 0; int c;
	c = gc();
	do n = 10 * n + (c & 0xf); while ((c = gc()) >= '0');
	return n;
}

// 数値のハッシュ関数
#define HASHSIZ 2000081
int hash[HASHSIZ+5], *hashend = hash + HASHSIZ;

int insert(int n) {
	int *p = hash + n % HASHSIZ;
	while (*p) {
		if (*p == n) return 1;
		if (++p == hashend) p = hash;
	}
	*p = n;
	return 0;
}

int main()
{
	int N;

	N = in();
	while (N--) {
		if (insert(in())) {
			puts("NO");
			return 0;
		}
	}
	puts("YES");
	return 0;
}


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

void q_sort(long numbers[], int left, int right);

int main(void){
  int j,N,K,i,min;
  long A[200000]={};
  long ans;
  if(scanf("%d",&N)>1){
    exit(0);
  }
  for(i=0;i<N;i++){
   if(scanf("%ld",&A[i])>1){
    exit(0);
   }
  }
  q_sort(A,0,N-1);
  for(i=0;i<N;i++){
      if(A[i]==A[i+1]){
	printf("NO");
	goto out;
      }
      if(i==N-1){
      printf("YES");
    }
  }
 out:
  return 0;
}

void q_sort(long numbers[], int left, int right)
{
    int l_hold, r_hold;
    long pivot,pa;

    l_hold = left;
    r_hold = right;
    pivot = numbers[left];
    while (left < right)
    {
        while ((numbers[right] >= pivot) && (left < right))
            right--;
        if (left != right)
        {
            numbers[left] = numbers[right];
            left++;
        }
        while ((numbers[left] <= pivot) && (left < right))
            left++;
        if (left != right)
        {
            numbers[right] = numbers[left];
            right--;
        }
   }
    numbers[left] = pivot;
    pivot = left;
    left = l_hold;
    right = r_hold;
    if (left < pivot)
      q_sort(numbers, left, pivot-1);
    if (right > pivot)
      q_sort(numbers, pivot+1, right);
}


#include<stdio.h>
#include<string.h>
void swap (int *x, int *y) {
  int temp;    // 値を一時保存する変数

  temp = *x;
  *x = *y;
  *y = temp;
}

/***
* pivotを決め、
* 全データをpivotを境目に振り分け、
* pivotの添え字を返す
***/
int partition (long array[], int left, int right) {
  int i, j, pivot;
  i = left;
  j = right + 1;
  pivot = left;   // 先頭要素をpivotとする

  do {
    do { i++; } while (array[i] < array[pivot]);
    do { j--; } while (array[pivot] < array[j]);
    // pivotより小さいものを左へ、大きいものを右へ
    if (i < j) { swap(&array[i], &array[j]); }
  } while (i < j);

  swap(&array[pivot], &array[j]);   //pivotを更新

  return j;
}

/* クイックソート */
void quick_sort (long array[], int left, int right) {
  int pivot;

  if (left < right) {
    pivot = partition(array, left, right);
    quick_sort(array, left, pivot-1);   // pivotを境に再帰的にクイックソート
    quick_sort(array, pivot+1, right);
  }
}

int main(void){
   int N,flag=0;
   long A[200001];
   scanf("%d",&N);
   for(int i=0;i<N;i++){
      scanf("%ld",&A[i]);
   }
   quick_sort(A,0,N-1);
   for(int i=0;i<N;i++){
      if(A[i]==A[i+1]){
         flag=1;
         break;
      }
   }
   if(flag==1){
      printf("NO");
   }else{
      printf("YES");
   }
   return 0;
}


#include<stdio.h>
#include<algorithm>
using namespace std;
int a[200000];
int main()
{
	int i,n,flag=0;
	scanf("%d",&n);
	for(i=0;i<n;i++)
	{
	  scanf("%d",&a[i]);
	}
	sort(a,a+n);
	for(i=0;i<n-1;i++)
	{
	   if(a[i]==a[i+1])
	   {
	      flag=1;
	      break;
	   }
	}
	if(flag==1)
	{
		printf("NO\n");
	}
	else
	{
		printf("YES\n");
	}
	return 0;
 }


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

//int cmp( const void *p, const void *q ) {
//    return *(int*)p - *(int*)q;
//}

int main(){

  int n,temp,i,j;

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

  int a[n];

  for(i=0;i<n;i++)
  {
    scanf("%d",&a[i]);
  }

  //qsort(a, n, sizeof(int), cmp);

  for (i=0;i<n;i++)
  {
  	for (j=i+1;j<n;j++)
    {
    	if (a[i]>a[j])
        {
        	temp=a[i];
          	a[i]=a[j];
          	a[j]=temp;
        }
    }
  }

	for (i=0;i<n;i++)
    {
    	//printf("%d ",a[i]);
      if (a[i]==a[i+1])
        {
         printf("NO");
          return 0;
        }
    }

  /*for (i=0;i<n;i++)
  {
    for (j=i+1;j<n;j++)
    {
       printf("a[%d]=%d a[%d]=%d\n",i,a[i],j,a[j]);
      if (a[i]==a[j])
      {
        printf("NO");
        return 0;
      }
    }

  }*/

 printf("YES");
 return 0;
}


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

int cmp( const void *p, const void *q ) {
    return *(int*)p - *(int*)q;
}

int main(){

  int n,temp,i,j;

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

  int a[n];

  for(i=0;i<n;i++)
  {
    scanf("%d",&a[i]);
  }

  qsort(a, n, sizeof(int), cmp);

  for (i=0;i<n;i++)
  {
  	for (j=i+1;j<n;j++)
    {
    	if (a[i]>a[j])
        {
        	temp=a[i];
          	a[i]=a[j];
          	a[j]=temp;
        }
    }
  }

	for (i=0;i<n;i++)
    {
    	//printf("%d ",a[i]);
      if (a[i]==a[i+1])
        {
         printf("NO");
          return 0;
        }
    }

  /*for (i=0;i<n;i++)
  {
    for (j=i+1;j<n;j++)
    {
       printf("a[%d]=%d a[%d]=%d\n",i,a[i],j,a[j]);
      if (a[i]==a[j])
      {
        printf("NO");
        return 0;
      }
    }

  }*/

 printf("YES");
 return 0;
}


function main(input) {
  const inputs =input.split('\n')
  const [N] = inputs[0].split(' ').map(Number)
  const A = inputs[1].split(' ').map(Number)
  const len = A.length
  const slen = (new Set(A)).size
  console.log(len === slen ? 'YES' : 'NO')
}

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


"use strict"
const create = () => {
    const input = require("fs").readFileSync("/dev/stdin", "utf8").trim().split("\n");
    const res = {
        "list": input, "index": 0, "max": input.length,
        "hasNext": function() {return this.index < this.max},
        "next": function() { if (!this.hasNext()) {throw "ArrayIndexOutOfBoundsException";}else{return this.list[this.index++];}}
    };
    return res;
}
const o = create();
const next = () => o.next()
const nextInt = () => parseInt(o.next())
const nextStrArray = () => o.next().split(" ")
const nextIntArray = () => o.next().split(" ").map(el => parseInt(el))
const nextCharArray = () => o.next().split("")
const hasNext = () => o.hasNext()
const myout = (...x) => console.log(...x)
const Main = () => {
    const N = nextInt()
    const x = nextIntArray()
    let a = x.length
    let s = new Set(x)
    let b = s.size
    if(a === b) console.log("YES")
    else console.log("NO")

}
Main()


// inputに入力データ全体が入る
function Main(input) {
  // inputを行ごとに分割しarrayに入れる
  input = input.split("\n");
  // input2行目の数字を個別に分けてarrayに入れる
  var num = input[1].split(" ");
  // setオブジェクトを作成
  var set = new Set(num);
  if (num.length == set.size) {
    console.log("YES");
  } else {
    console.log("NO");
  };
}
//*この行以降は編集しないでください（標準入出力から一度に読み込み、Mainを呼び出します）
Main(require("fs").readFileSync("/dev/stdin", "utf8"));


function Main(input) {
	input = input.split("\n");
  	tmp = input[1].split(" ");
 	tmp.sort(function(a,b){
        if( a < b ) return -1;
        if( a > b ) return 1;
        return 0;
	});
    for(let i =1 ; i<tmp.length;i++){
      if(tmp[i]===tmp[i-1]){
        console.log("No");
        return;
      }
      console.log("Yes");
      return;
    }

}
//*この行以降は編集しないでください（標準入出力から一度に読み込み、Mainを呼び出します）
Main(require("fs").readFileSync("/dev/stdin", "utf8"));


function Main(input) {
	input = input.split("\n");
  	tmp = input[1].split(" ");
 	let kensa;
  	for(let i = 0; i < tmp.length; i++){
      kensa = tmp[0];
      tmp.shift();
      console.log(tmp);
      if(tmp.indexOf(kensa) !== -1){
        console.log("No");
        return;
      }
    }

	console.log("Yes");
}
//*この行以降は編集しないでください（標準入出力から一度に読み込み、Mainを呼び出します）
Main(require("fs").readFileSync("/dev/stdin", "utf8"));


function Main(input) {
  input=input.split("\n");
  if(input[input.length-1]===''){
    input.pop();
  }
  const N=input[0];
  const array=input[1].split(' ').map(e=>{
    return e-0;
  });
  var memo=[];
  var message='YES';
  array.forEach(e=>{
    for(var i=0;i<memo.length;i++){
      if(memo[i]===e){
        message='NO';
        break;
      }else if(memo[i]>e){
        memo.splice(i,0,e);
        break;
      }
      if(i===memo.length-1){
        memo.push(e);
        break;
      }
    }
    if(memo.length===0){
      memo=[e];
    }
  });
  console.log(message);

}

//*この行以降は編集しないでください（標準入出力から一度に読み込み、Mainを呼び出します）
Main(require("fs").readFileSync("/dev/stdin", "utf8"));


package main

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

var sc = bufio.NewScanner(os.Stdin)

func Scan() string {
	sc.Scan()
	return sc.Text()
}
func iScan() int {
	n, _ := strconv.Atoi(Scan())
	return n
}
func fScan() float64 {
	n, _ := strconv.ParseFloat(Scan(), 64)
	return n
}
func stringToInt(s string) int {
	n, _ := strconv.Atoi(s)
	return n
}
func SScan(n int) []string {
	a := make([]string, n)
	for i := 0; i < n; i++ {
		a[i] = Scan()
	}
	return a
}
func iSScan(n int) []int {
	a := make([]int, n)
	for i := 0; i < n; i++ {
		a[i] = iScan()
	}
	return a
}
func abs(x int) int {
	if x < 0 {
		x = -x
	}
	return x
}
func larger(a, b int) int {
	if a < b {
		return b
	} else {
		return a
	}
}
func smaller(a, b int) int {
	if a > b {
		return b
	} else {
		return a
	}
}
func max(a []int) int {
	x := a[0]
	for i := 0; i < len(a); i++ {
		if x < a[i] {
			x = a[i]
		}
	}
	return x
}
func min(a []int) int {
	x := a[0]
	for i := 0; i < len(a); i++ {
		if x > a[i] {
			x = a[i]
		}
	}
	return x
}
func sum(a []int) int {
	x := 0
	for _, v := range a {
		x += v
	}
	return x
}

var mod int = 1000000007

func main() {
	buf := make([]byte, 0)
	sc.Buffer(buf, mod)
	sc.Split(bufio.ScanWords)
	n := iScan()
	a := iSScan(n)
	d := make(map[int]struct{})
	for _, v := range a {
		d[v] = struct{}{}
	}
	if len(d) == len(a) {
		fmt.Println("YES")
	} else {
		fmt.Println("NO")
	}
}


package main

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

func main() {
	n := readI()
	a := make(map[int]bool)
	for i := 0; i < n; i++ {
		tmp := readI()
		if _, ok := a[tmp]; ok {
			fmt.Println("NO")
			return
		}
		a[tmp] = true
	}
	fmt.Println("YES")
}

/*-----------Input utils-----------*/

var sc = bufio.NewScanner(os.Stdin)

func init() {
	if len(os.Args) >= 2 {
		if os.Args[1] == "debug" {
			debug()
		}
	}
	const buf = 200100
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, buf), buf)
}

func debug() {
	testFile, err := os.Open("./test/sample-1.in")
	if err != nil {
		fmt.Fprintln(os.Stderr, "There is no testfile.")
		os.Exit(1)
	}
	sc = bufio.NewScanner(testFile)
}

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

func readR() []rune {
	return []rune(readS())
}

func readI() int {
	i, _ := strconv.Atoi(readS())
	return i
}

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


package main

import (
	"bufio"
	"os"
	//"sort"
	"strconv"
)

var sc = bufio.NewScanner(os.Stdin)

func scanInt() int {
	iv, _ := strconv.Atoi(scanString())
	return iv
}

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

func init() {
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, 100001), 100001*100)
}

func calcmax(a, b int) int {
	if a > b {
		return a
	} else {
		return b
	}
}

func main() {
	var N, A int
	N = scanInt()
	m := map[int]int {}
    var wr = bufio.NewWriter(os.Stdout)
	for i := 0; i < N; i++ {
		A = scanInt()
		if m[A] == 0 {
			m[A]++
		} else {
			wr.WriteString("NO\n")
	        wr.Flush()
			return
		}
	}
	wr.WriteString("YES\n")
	wr.Flush()
}


package main

import (
	"fmt"
	"sort"
)

func main() {
	var N int
	fmt.Scan(&N)
	A := make([]int, N)
	for i := range A {
		fmt.Scan(&A[i])
	}
	sort.Slice(A, func(i, j int) bool { return A[i] < A[j] })
	for i := 1; i < N; i++ {
		if A[i] == A[i-1] {
			fmt.Println("No")
			return
		}
	}
	fmt.Println("Yes")
}


package main

import (
	"fmt"
	"sort"
)

func main() {

	var N int
	fmt.Scanf("%d", &N)

	A := make([]int, N)
	for i := 0; i < N; i++ {
		fmt.Scanf("%d", &A[i])
	}

	sort.Ints(A)
	var flag int = 0
	for i := 0; i < N-1; i++ {
		if A[i] == A[i+1] {
			flag = 1
		}
	}

	if flag == 1 {
		fmt.Println("No")
	} else {
		fmt.Println("Yes")
	}
}


package main

import (
	"fmt"
)

func main() {
	var N int
	m := make(map[int]int)
	fmt.Scan(&N)

	yesOrNo := true
	for i := 0; i < N; i++ {
		var val int
		fmt.Scan("%d", &val)
		m[val] = m[val] + 1
		if m[val] > 1 {
			yesOrNo = false
		}
	}

	if yesOrNo {
		fmt.Println("YES")
	} else {
		fmt.Println("NO")
	}
}


puts gets.to_i==gets.chomp.split.uniq.size ? 'YES' : 'NO'


n = gets.to_i
arr = gets.chomp.split(' ')
if arr.size == arr.uniq.size
  puts "YES"
else
  puts "NO"
end


gets.to_i
ary=gets.split.map(&:to_i)
puts ary.size==ary.uniq.size ? 'YES' : 'NO'


puts gets.to_i==gets.chomp.split.uniq.size ? 'Yes' : 'No'


puts gets.to_i==gets.chomp.split.uniq.size ?'Yes':'No'


gets
a = gets.split.map(&:to_i)

if a.size == a.uniq.size
    puts 'Yes'
else
    puts 'No'
end


//  ____            _                  _                       _       _
// |  _ \ _   _ ___| |_    ___ _ __   | |_ ___ _ __ ___  _ __ | | __ _| |_ ___
// | |_) | | | / __| __|  / __| '_ \  | __/ _ \ '_ ` _ \| '_ \| |/ _` | __/ _ \
// |  _ <| |_| \__ \ |_  | (__| |_) | | ||  __/ | | | | | |_) | | (_| | ||  __/
// |_| \_\\__,_|___/\__|  \___| .__/___\__\___|_| |_| |_| .__/|_|\__,_|\__\___|
//                            |_| |_____|               |_|

//https://github.com/manta1130/Competitive_Programming_Template_Rust

#[macro_use]
mod input {

    use std;
    use std::io;

    const SPLIT_DELIMITER: char = ' ';

    #[macro_export]
    #[allow(unused_macros)]
    macro_rules! input {
    ( $($x:expr ),*) => {
        {
            let temp_str = input_line_str();
            let mut split_result_iter = temp_str.split_whitespace();
                $(
                let buf_split_result = split_result_iter.next();
                let buf_split_result = buf_split_result.unwrap();
                    ($x) = buf_split_result.parse().unwrap();
                )*
        }
    };
}

    #[allow(dead_code)]
    pub fn input_line_str() -> String {
        let mut s = String::new();
        io::stdin().read_line(&mut s).unwrap();
        s.trim().to_string()
    }

    #[allow(dead_code)]
    pub fn p<T>(t: T)
    where
        T: std::fmt::Display,
    {
        println!("{}", t);
    }

    #[allow(dead_code)]
    pub fn input_vector2d<T>(line: usize) -> Vec<Vec<T>>
    where
        T: std::str::FromStr,
    {
        let mut v: Vec<Vec<T>> = Vec::new();

        for _ in 0..line {
            let vec_line = input_vector();
            v.push(vec_line);
        }
        v
    }

    #[allow(dead_code)]
    pub fn input_vector<T>() -> Vec<T>
    where
        T: std::str::FromStr,
    {
        let mut v: Vec<T> = Vec::new();

        let s = input_line_str();
        let split_result = s.split(SPLIT_DELIMITER);
        for z in split_result {
            let buf = match z.parse() {
                Ok(r) => r,
                Err(_) => panic!("Parse Error"),
            };
            v.push(buf);
        }
        v
    }

    #[allow(dead_code)]
    pub fn input_vector_row<T>(n: usize) -> Vec<T>
    where
        T: std::str::FromStr,
    {
        let mut v = Vec::with_capacity(n);
        for _ in 0..n {
            let buf = match input_line_str().parse() {
                Ok(r) => r,
                Err(_) => panic!("Parse Error"),
            };
            v.push(buf);
        }
        v
    }

    pub trait ToCharVec {
        fn to_charvec(&self) -> Vec<char>;
    }

    impl ToCharVec for String {
        fn to_charvec(&self) -> Vec<char> {
            self.to_string().chars().collect::<Vec<_>>()
        }
    }
}

use input::*;
use std::collections::HashSet;

fn main() {
    let n: usize;
    input!(n);
    let a = input_vector::<usize>();
    let a = a.iter().collect::<HashSet<_>>();
    if a.len() == n {
        println!("YES");
    } else {
        println!("NO");
    }
}


#[macro_use]
mod input_mcr {
    // ref: tanakh <https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8>
    // diff: using Parser
    #[macro_export(local_inner_macros)]
    macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
        let mut parser = Parser::from_str($s);
        input_inner!{parser, $($r)*}
    };
    (parser = $parser:ident, $($r:tt)*) => {
        input_inner!{$parser, $($r)*}
    };
    (new_stdin_parser = $parser:ident, $($r:tt)*) => {
        let stdin = std::io::stdin();
        let reader = std::io::BufReader::new(stdin.lock());
        let mut $parser = Parser::new(reader);
        input_inner!{$parser, $($r)*}
    };
    ($($r:tt)*) => {
        input!{new_stdin_parser = parser, $($r)*}
    };
}

    #[macro_export(local_inner_macros)]
    macro_rules! input_inner {
    ($parser:ident) => {};
    ($parser:ident, ) => {};
    ($parser:ident, $var:ident : $t:tt $($r:tt)*) => {
        let $var = read_value!($parser, $t);
        input_inner!{$parser $($r)*}
    };
}

    #[macro_export(local_inner_macros)]
    macro_rules! read_value {
    ($parser:ident, ( $($t:tt),* )) => {
        ( $(read_value!($parser, $t)),* )
    };
    ($parser:ident, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($parser, $t)).collect::<Vec<_>>()
    };
    ($parser:ident, chars) => {
        read_value!($parser, String).chars().collect::<Vec<char>>()
    };
    ($parser:ident, char_) => {
        read_value!($parser, String).chars().collect::<Vec<char>>()[0]
    };
    ($parser:ident, usize1) => {
        read_value!($parser, usize) - 1
    };
    ($parser:ident, i64_) => {
        $parser.fast_i64()
    };
    ($parser:ident, usize_) => {
        $parser.fast_i64() as usize
    };
    ($parser:ident, usize1_) => {
        ($parser.fast_i64() - 1) as usize
    };
    ($parser:ident, $t:ty) => {
        $parser.next::<$t>().expect("Parse error")
    };
}

    use std::io;
    use std::io::BufRead;
    use std::str;

    // ref: tatsuya6502 <https://qiita.com/tatsuya6502/items/cd448486f7ef7b5b8c7e>
    // ref: wariuni <https://qiita.com/tatsuya6502/items/cd448486f7ef7b5b8c7e#comment-7040a5ae96305e884eb9>
    // diff: using std::io::BufRead::fill_buf()
    pub struct Parser<R> {
        pub reader: R,
        buf: Vec<u8>,
        pos: usize,
    }

    impl Parser<io::Empty> {
        pub fn from_str(s: &str) -> Parser<io::Empty> {
            Parser {
                reader: io::empty(),
                buf: s.as_bytes().to_vec(),
                pos: 0,
            }
        }
    }

    impl<R: BufRead> Parser<R> {
        pub fn new(reader: R) -> Parser<R> {
            Parser {
                reader: reader,
                buf: vec![],
                pos: 0,
            }
        }
        pub fn update_buf(&mut self) {
            self.buf.clear();
            self.pos = 0;
            loop {
                let (len, complete) = {
                    let buf2 = self.reader.fill_buf().unwrap();
                    self.buf.extend_from_slice(buf2);
                    let len = buf2.len();
                    (len, buf2[len - 1] <= 0x20)
                };
                self.reader.consume(len);
                if complete {
                    break;
                }
            }
        }
        pub fn next<T: str::FromStr>(&mut self) -> Result<T, T::Err> {
            loop {
                let mut begin = self.pos;
                while begin < self.buf.len() && (self.buf[begin] <= 0x20) {
                    begin += 1;
                }
                let mut end = begin;
                while end < self.buf.len() && (self.buf[end] > 0x20) {
                    end += 1;
                }
                if begin != self.buf.len() {
                    self.pos = end;
                    return unsafe { str::from_utf8_unchecked(&self.buf[begin..end]) }.parse::<T>();
                } else {
                    self.update_buf();
                }
            }
        }
        pub fn fast_i64(&mut self) -> i64 {
            loop {
                let mut begin = self.pos;
                while begin < self.buf.len() && (self.buf[begin] <= 0x20) {
                    begin += 1;
                }
                if begin == self.buf.len() {
                    self.update_buf();
                    continue;
                }
                let mut res = 0;
                let (is_positive, mut end) = match self.buf[begin] {
                    b'+' => (true, begin + 1),
                    b'-' => (false, begin + 1),
                    _ => (true, begin),
                };
                while end < self.buf.len() && (self.buf[end] > 0x20) {
                    res = res * 10 + (self.buf[end] as i64 - '0' as i64);
                    end += 1;
                }
                if begin != self.buf.len() {
                    self.pos = end;
                    return if is_positive { res } else { -res };
                } else {
                    self.update_buf();
                }
            }
        }
    }
}

mod next_permutation {
    pub fn next_permutation<T: Ord>(xs: &mut [T]) -> bool {
        let n = xs.len();
        for i in (1..n).rev() {
            if xs[i - 1] < xs[i] {
                let mut s = None;
                for k in (i..n).rev() {
                    if xs[i - 1] < xs[k] && (s.is_none() || xs[k] < xs[s.unwrap()]) {
                        s = Some(k);
                    }
                }
                let s = s.unwrap();
                xs.swap(i - 1, s);
                xs[i..].reverse();
                return true;
            }
        }
        xs.reverse();
        false
    }
}

use input_mcr::*;
use std::cmp::*;

use next_permutation::*;

fn main() {
    input! {
        n: usize,
        xs: [i64; n],
    }
    let mut res = true;
    let mut xs = xs;
    xs.sort();
    for i in 1..n {
        if xs[i - 1] == xs[i] {
            res = false;
        }
    }
    println!("{}", if res { "YES" } else { "NO" });
}