/*------------------------------------------------------------------*/
/*------------------------- begin template -------------------------*/
/*------------------------------------------------------------------*/

// ref: tanakh <https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8>
// diff: using Parser
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_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_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();
            }
        }
    }
}

#[allow(unused_imports)]
use std::cmp::*;
use std::ops::*;

pub fn gen_cum<T: Add<Output = T> + Copy>(zero: T, xs: &Vec<T>) -> Vec<T> {
    let mut res = vec![zero; xs.len() + 1];
    for (i, &x) in xs.iter().enumerate() {
        res[i + 1] = res[i] + x;
    }
    res
}

fn main() {
    input! {
        new_stdin_parser = parser,
    }
    let res = solve(&mut parser);
    print!("{}", res);
}

/*------------------------------------------------------------------*/
/*-------------------------- end template --------------------------*/
/*------------------------------------------------------------------*/

use std::fmt::Write;
fn solve<R: BufRead>(parser: &mut Parser<R>) -> String {
    let mut buf = String::new();
    input! {
        parser = parser,
        n: usize,
        xs: [i64; n],
    }
    let ys: Vec<i64> = xs.iter().map(|&x| x.abs()).collect();
    let ys_cum = gen_cum(0, &ys);
    {
        let mut has_zero = false;
        for &x in &xs {
            if x == 0 {
                has_zero = true;
            }
        }
        if has_zero {
            writeln!(buf, "{}", ys_cum[n]);
            return buf;
        }
    }
    let parity = xs.iter().map(|&x| if x < 0 { 1 } else { 0 }).sum::<i64>() % 2;
    let parity_sign = ((parity * 2) - 1) * -1;
    let mut res = -(1i64 << 50);
    for i in 0..n {
        let sign = xs[i] / xs[i].abs();
        let t = ys_cum[n] - xs[i].abs() + xs[i] * parity_sign * sign;
        // eprintln!("i={}, t={}", i, t);
        res = max(res, t);
    }
    writeln!(buf, "{}", res);
    buf
}


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

pub fn main() {
    let i = stdin();
    let mut o = Vec::new();
    run(i.lock(), &mut o);
    stdout().write_all(&o).unwrap();
}

fn run<R: BufRead, W: Write>(i: R, o: &mut W) {
    let mut i = CpReader::new(i);
    let n = i.read::<usize>();
    let a = i.read_vec::<isize>(n);
    writeln!(o, "{}", solve(&a)).unwrap();
}
fn solve(a: &[isize]) -> isize {
    let mut abs_sum = 0;
    let mut abs_min = isize::max_value();
    let mut negative_count = 0;
    for &a in a {
        let abs = if a < 0 {
            negative_count += 1;
            -a
        } else {
            a
        };
        abs_sum += abs;
        abs_min = min(abs_min, abs);
    }

    if negative_count % 2 != 0 {
        abs_sum -= abs_min * 2;
    }
    abs_sum
}

mod utils {
    use super::*;

    pub struct CpReader<R: BufRead> {
        r: R,
        s: String,
    }

    macro_rules! fn_read {
        { $f:ident($($t:ident),*) } => {
            #[allow(dead_code)]
            pub fn $f<$($t: FromStr),*>(&mut self) -> ($($t),*) {
                let i = &mut self.read_line().split(' ');
                ($(read_next::<$t,_>(i)),*)
            }
        };
    }

    impl<R: BufRead> CpReader<R> {
        pub fn new(r: R) -> Self {
            CpReader {
                r: r,
                s: String::new(),
            }
        }
        pub fn read_line(&mut self) -> &str {
            self.s.clear();
            self.r.read_line(&mut self.s).unwrap();
            self.s.trim()
        }

        pub fn read<T: FromStr>(&mut self) -> T {
            self.read_line().parse().ok().unwrap()
        }
        fn_read! { read2(T1, T2) }
        fn_read! { read3(T1, T2, T3) }
        fn_read! { read4(T1, T2, T3, T4) }
        fn_read! { read5(T1, T2, T3, T4, T5) }

        pub fn read_vec<T: FromStr>(&mut self, n: usize) -> Vec<T> {
            self.read_line()
                .split(' ')
                .take(n)
                .map(|x| x.parse().ok().unwrap())
                .collect()
        }
    }
    fn read_next<'a, T: FromStr, I: Iterator<Item = &'a str>>(i: &mut I) -> T {
        i.next().unwrap().parse().ok().unwrap()
    }

}


macro_rules! debug {
    ( $x:ident [ $i:expr ] ) => {
        if cfg!(debug_assertions) {
            println!("{}[{}] = {}", stringify!($x), $i, $x[$i]);
        }
    };
    ( $x:ident [ $i:expr ][ $j:expr ] ) => {
        if cfg!(debug_assertions) {
            println!("{}[{}][{}] = {}", stringify!($x), $i, $j, $x[$i][$j]);
        }
    };
    ( $x:expr ) => {
        if cfg!(debug_assertions) {
            println!("{}:{} {} = {:?}", line!(), column!(), stringify!($x), $x);
        }
    };
}

fn main() {
    let stdin = std::io::stdin();
    let mut stdin = my::io::InputReader::new(stdin.lock());

    let N: usize = stdin.read();
    let mut A: Vec<i64> = Vec::<i64>::new();
    let mut p = 0; // #{i | A[i] > 0}
    let mut m = 0; // #{i | A[i] < 0}
    let mut z = 0; // #{i | A[i] == 0}
    for i in 0..N {
        A.push(stdin.read());
        if A[i] > 0 {
            p += 1;
        } else if A[i] < 0 {
            m += 1;
        } else {
            z += 1;
        }
    }
    let s: i64 = A.iter().map(|x| x.abs()).sum();
    let result = if z > 0 || m % 2 == 0 {
        s
    } else {
        s - 2 * A.iter().map(|x| x.abs()).min().unwrap()
    };
    println!("{}", result);
}

mod my {
    pub mod io {
        use std::io::{BufRead, ErrorKind, Result};
        use std::str::{FromStr, from_utf8};
        use std::fmt::Debug;

        pub fn read_word<R: BufRead>(r: &mut R, buf: &mut Vec<u8>)
                                              -> Result<usize> {
            let mut read = 0;
            loop {
                let (done, used) = {
                    let available = match r.fill_buf() {
                        Ok(n) => n,
                        Err(ref e) if e.kind() == ErrorKind::Interrupted => continue,
                        Err(e) => return Err(e)
                    };
                    match available.iter().position(|&x| x == b'\n' || x == b' ') {
                        Some(i) => {
                            buf.extend_from_slice(&available[..i]);
                            (true, i + 1)
                        }
                        None => {
                            buf.extend_from_slice(available);
                            (false, available.len())
                        }
                    }
                };
                r.consume(used);
                read += used;
                if done || used == 0 {
                    return Ok(read);
                }
            }
        }

        pub struct InputReader<R: BufRead> {
            reader: R,
            buf: Vec<u8>,
        }

        impl<R: BufRead> InputReader<R> {
            pub fn new(reader: R) -> InputReader<R> {
                InputReader {
                    reader: reader,
                    buf: Vec::<u8>::new(),
                }
            }

            pub fn read_word(&mut self) {
                read_word(&mut self.reader, &mut self.buf);
            }

            pub fn read<T>(&mut self) -> T
                where T: FromStr,
                      T::Err: Debug
            {
                self.buf.clear();
                self.read_word();
                from_utf8(&self.buf).unwrap().trim().parse().unwrap()
            }
        }
    }
}


use proconio::input;

fn main() {
  input! {
    n: usize,
    vals: [isize;n]
  }

  let mut minus_count = 0;
  let mut total = 0;
  let mut min = isize::max_value();
  for v in vals.iter() {
    if v < &0 {
      minus_count += 1;
    }
    let abs_v = v.abs();
    min = std::cmp::min(min, abs_v);
    total += abs_v;
  }

  if minus_count % 2 == 0 {
    println!("{}", total);
  } else {
    println!("{}", total - min);
  }
}


use std::cmp::min;
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)*}
    };

    ($next:expr, mut $var:ident : $t:tt $($r:tt)*) => {
        let mut $var = read_value!($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! {
    n: usize,
    a: [i64; n]
    }
    let mut ans = 0;
    let mut m = std::i64::MAX;
    let mut c = 0;
    for i in 0..n {
        ans += a[i].abs();
        m = min(a[i].abs(), m);
        if a[i] < 0 {
            c += 1;
        }
    }
    if c % 2 == 1 { ans -= m }
    println!("{}", ans);

}


use proconio::{input, fastout};
// use itertools::*;

#[fastout]
fn main() {
  input!{
    n: usize,
    a: [i32; n]
  };
  let mut sign = 0;
  for i in &a {
    if i < &0 {
      sign += 1;
    }
  }
  dbg!(sign);
  let ans : u64 = if sign % 2 == 0 {
    a.iter().map(|x| x.abs() as u64).sum()
  } else {
    let mut v = a.iter().map(|x| x.abs() as u64).collect::<Vec<u64>>();
    v.sort();
    v.iter().sum::<u64>() - v[0] * 2
  };
  println!("{}", ans);
}


_ = readLine()!
var a = readLine()!.split(separator: " ").compactMap { Int($0) }

let minusCount = a.lazy.filter { $0 < 0 }.count

if minusCount % 2 == 0 {
    print(a.lazy.map(abs).reduce(0, +))
} else {
    let sorted = a.lazy.map(abs).sorted()
    let head = sorted.first!
    let tail = sorted.lazy.dropFirst()
    print(tail.reduce(-head, +))
}


import Foundation

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

let absolutes = A.map { abs($0) }
let sum = absolutes.reduce(0, +)
let min = absolutes.min()!
let isEven = A.filter({ $0.signum() == -1 }).count % 2 == 0

let answer = isEven ? sum : sum - min * 2

print(answer)


let N = Int(readLine()!)!
let A = readLine()!.characters.split(" ").map{Int(String($0))!}
if A.filter({$0<0}).count % 2 == 0 {
    print(A.reduce(0){$0+abs($1)})
} else {
    print(A.reduce(0){$0+abs($1)}-A.map{abs($0)}.minElement()!*2)
}


_ = readLine()!
var a = readLine()!.split(separator: " ").compactMap { Int($0) }

for i in 0..<a.count - 1 {
    let curr = a[i]
    let next = a[i + 1]
    if curr == 0 && next == 0 {
    } else if curr == 0 && next < 0 {
        a[i] *= -1
        a[i + 1] *= -1
    } else if curr == 0 && next > 0 {
    } else if curr < 0 && next == 0 {
        a[i] *= -1
        a[i + 1] *= -1
    } else if curr < 0 && next < 0 {
        a[i] *= -1
        a[i + 1] *= -1
    } else if curr < 0 && next > 0 {
        if -curr >= next {
            a[i] *= -1
            a[i + 1] *= -1
        }
    } else if curr > 0 && next == 0 {
    } else if curr > 0 && next < 0 {
    } else if curr > 0 && next > 0 {
    }
}

print(a.reduce(0, +))


_ = readLine()!
var a = readLine()!.split(separator: " ").compactMap { Int($0) }

for i in 0..<a.count - 1 {
    let curr = a[i]
    let next = a[i + 1]
    if curr <= 0 && next < 0 {
        a[i] *= -1
        a[i + 1] *= -1
    } else if curr < 0 && next >= 0 {
        if -curr >= next {
            a[i] *= -1
            a[i + 1] *= -1
        }
    }
}

print(a.reduce(0, +))


_ = readLine()!
var a = readLine()!.split(separator: " ").compactMap { Int($0) }

print(a.lazy.map(abs).reduce(0, +))


export class Main {
  static main(input): string {
    const tmp: string[] = input.split("\n");
    const n: number = Number(tmp[0]);
    const a: number[] = tmp[1].split(" ").map(Number);
    let min: number = Infinity;
    let result: number = 0;
    let even: boolean = true;
    let hasZero: boolean = false;
    for (let i = 0; i < n; ++i) {
      if (a[i] < 0) {
        even = !even;
      } else if (a[i] == 0) {
        hasZero = true;
      }
      const b: number = Math.abs(a[i]);
      if (b < min) {
        min = b;
      }
      result += b;
    }
    return `${result - (hasZero || even ? 0 : (min * 2))}`;
  }
}
console.log(Main.main(require("fs").readFileSync("/dev/stdin", "utf8")));


import * as fs from 'fs';

function Picker(input) {
  var lines = input.split('\n');
  var fields = lines.reduce(function(all, line) { return all.concat(line.split(' ')); }, []);
  var p = 0;

  return {
    int: function() {
      return parseInt(fields[p++], 10);
    },
    float: function() {
      return parseFloat(fields[p++]);
    },
    str: function() {
      return fields[p++];
    }
  };
}

const input = fs.readFileSync("/dev/stdin", "utf8");
const pick = Picker(input);

//////////////////////////////////////////

const n = pick.int();
const a = new Array(n).fill(0).map(() => pick.int());

let neg = 0;
let sum = 0;
let min = Infinity;
for (let i = 0; i < n; ++i) {
  if (a[i] < 0) {
    neg++;
  }
  sum += Math.abs(a[i]);
  min = Math.abs(a[i]) < min ? Math.abs(a[i]) : min;
}

if (neg % 2 === 1) {
  sum -= min * 2;
}

/*
const negatives = a.filter(e => e < 0).length;

let sum;
sum = a.map(e => e > 0 ? e : -e).reduce((a, b) => a + b);

if (negatives % 2) {
  const min = a.map(e => e > 0 ? e : -e).sort((a, b) => b - a).pop();
  sum -= min * 2;
}
*/

console.log(sum);


var main = (lines) => {
	var N = Number(lines[0])
    var As = lines[1].split(" ").map(Number)
    const isOdd = Boolean(As.filter(x=>x<0).length % 2)
    let minNum = Infinity
    let result = As.reduce((acc,x)=>{
      const absx = Math.abs(x)
      if (absx < minNum) minNum = absx
      return acc + absx
    }, 0)
  	if(isOdd) result -= minNum * 2
  console.log(result)
}

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


import * as fs from 'fs';

function Picker(input) {
  var lines = input.split('\n');
  var fields = lines.reduce(function(all, line) { return all.concat(line.split(' ')); }, []);
  var p = 0;

  return {
    int: function() {
      return parseInt(fields[p++], 10);
    },
    float: function() {
      return parseFloat(fields[p++]);
    },
    str: function() {
      return fields[p++];
    }
  };
}

const input = fs.readFileSync("/dev/stdin", "utf8");
const pick = Picker(input);

//////////////////////////////////////////

const n = pick.int();
const a = new Array(n).fill(0).map(() => pick.int());

const negatives = a.filter(e => e < 0).length;

let sum;
sum = a.map(e => e > 0 ? e : -e).reduce((a, b) => a + b);

if (negatives % 2) {
  const min = a.map(e => e > 0 ? e : -e).sort((a, b) => b - a).pop();
  sum -= min * 2;
}

console.log(sum);


import * as fs from 'fs';

function Picker(input) {
  var lines = input.split('\n');
  var fields = lines.reduce(function(all, line) { return all.concat(line.split(' ')); }, []);
  var p = 0;

  return {
    int: function() {
      return parseInt(fields[p++], 10);
    },
    float: function() {
      return parseFloat(fields[p++]);
    },
    str: function() {
      return fields[p++];
    }
  };
}

const input = fs.readFileSync("/dev/stdin", "utf8");
const pick = Picker(input);

//////////////////////////////////////////

const n = pick.int();
const a = new Array(n).fill(0).map(() => pick.int());

const negatives = a.filter(e => e < 0).length;
const containsZero = a.some(e => e === 0);

let sum;
sum = a.map(e => e > 0 ? e : -e).reduce((a, b) => a + b);

if (negatives % 2 && !containsZero) {
  const min = a.map(e => e > 0 ? e : -e).sort((a, b) => b - a).pop();
  sum -= min * 2;
}

console.log(sum);


def main():
    import sys
    S=sys.stdin.readline()
    T=sys.stdin.readline()
    count=0
    for s,t in zip(S,T):
        count+=s!=t
    print(count)
main()


S = input()
T = input()

print(len([0 for s, t in zip(S, T) if s != t]))


#!/usr/bin/env python3
print(len([1 for s, t in zip(input(), input()) if s != t]))


str1 = input()
str2 = input()

i = 0
for _ in str1:
  if _ not in str2:
    i += 1
print(i)


s=list(input())
t=list(input())
u=len(s)
ans=0
for i in range(u):
  if s[u] != t[u]:
    ans+=1

print(ans)


S = input()
T = input()
count = 0
for s, t in S, T:
  if s != t:
    count += 1
print(count)


import sun.rmi.runtime.Log;

import java.io. *;
import java.util.*;
import static java.lang.Math.*;
public class Main {

    static final FastReader sc = new FastReader(System.in);
    static final PrintWriter pw = new PrintWriter(System.out);

    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<>();
            color = new int[V];
            q.add(new edge(src,0));
            color[src] = 0;
            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]==color[u]){
                        color[adj.get(u).get(i).dest] = color[u]+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] = 1;
            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]==0) {
                        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;
    }

    static int[] phi;

    static void generatePhi(int n){
        phi = new int[n+1];

        for(int i = 0; i<=n; i++){
            phi[i] = i;
        }

        for(int i=2; i<=n; i++){
            if(phi[i]==i){
                for(int j= i; j<=n; j+=i){
                    phi[j] -= (phi[j]/i);
                }
            }
        }
    }

    static int gcdCount(int n, int d){
        return phi[n/d];
    }

    static boolean prime[];
    static int smallestFactor[];

    static void sieveOfEratosthenes(int n)
    {
        prime = new boolean[n+1];
        smallestFactor = new int[n+1];

        smallestFactor[1] = 1;
        for(int i=2;i<n;i++) {
            prime[i] = true;
            smallestFactor[i] = i;
        }

        for(int p = 2; p*p <=n; p++)
        {
            if(prime[p])
            {
                smallestFactor[p] = p;
                for(int i = p*p; i <= n; i += p) {
                    prime[i] = false;
                    smallestFactor[i] = min(p,smallestFactor[i]);
                }
            }
        }

    }

    static double Logx(double n, int x){
        return log(n)/log(x);
    }

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

    public static void main(String[] args) {

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

        int l = min(s.length(),t.length());

        char a[] = s.toCharArray();
        char b[] = t.toCharArray();
        int count = 0;
        for(int i = 0; i<l; i++){
            if(a[i]!=b[i]){
                count++;
            }
        }

        count+=max(s.length(),t.length())-min(s.length(),t.length());
        pw.println(count);

        pw.flush();

    }

    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.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.*;
import java.io.*;
import java.math.*;
public class Main {
    InputStream is;
    PrintWriter out;
    String INPUT = "";
    //class  Declaration

    static class pair implements Comparable < pair > {
        long x;
        long y;

        pair(long i, long j) {
            x = i;
            y = j;

        }
        public int compareTo(pair p) {
            if (this.x != p.x) {
                return (int)(this.x-p.x);
            } else {
                return (int)(this.y - p.y);
            }
        }
        public int hashCode() {
            return (x + " " + y).hashCode();
        }
        public String toString() {
            return x + " " + y;
        }
        public boolean equals(Object o) {
            pair x = (pair) o;
            return (x.x == this.x && x.y == this.y);
        }
    }
    // int[] dx = {0,0,1,-1};
    // int[] dy = {1,-1,0,0};
    // int[] ddx = {0,0,1,-1,1,-1,1,-1};
    // int[] ddy = {1,-1,0,0,1,-1,-1,1};

int inf = (int) 1e9 + 5;
long mod =  (int)1e9 + 9;

void solve() throws Exception {
    char[] a= ns().toCharArray();
    char[] b= ns().toCharArray();
    int cnt =0;
    for(int i=0;i<a.length;++i){
        if(a[i]!=b[i]) cnt++;
    }
    pn(cnt);

}
    long pow(long a, long b) {
        long result = 1;
        while (b > 0) {
            if (b % 2 == 1) result = (result * a) % mod;
            b /= 2;
            a = (a * a) % mod;
        }
        return result;
    }

    void print(Object o) {
        System.out.println(o);
        System.out.flush();
    }

    long gcd(long a, long b) {
        if (b == 0)
            return a;
        return gcd(b, a % b);
    }
    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();
    }

    //output methods
    private void pn(Object o) {
        out.println(o);
    }
    private void p(Object o) {
        out.print(o);
    }
    private ArrayList < ArrayList < Integer >> ng(int n, int e) {
        ArrayList < ArrayList < Integer >> g = new ArrayList < > ();
        for (int i = 0; i <= n; ++i) g.add(new ArrayList < > ());

        for (int i = 0; i < e; ++i) {
            int u = ni(), v = ni();
            g.get(u).add(v);
            g.get(v).add(u);
        }

        return g;
    }

    private ArrayList < ArrayList < pair >> nwg(int n, int e) {
        ArrayList < ArrayList < pair >> g = new ArrayList < > ();
        for (int i = 0; i <= n; ++i) g.add(new ArrayList < > ());

        for (int i = 0; i < e; ++i) {
            int u = ni(), v = ni(), w = ni();
            g.get(u).add(new pair(w, v));
            g.get(v).add(new pair(w, u));
        }

        return g;
    }

    //input methods
    private byte[] inbuf = new byte[1024];
    public 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))) { // when nextLine, (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 void tr(Object...o) {
        if (INPUT.length() > 0) System.out.println(Arrays.deepToString(o));
    }
    void watch(Object...a) throws Exception {
        int i = 1;
        print("watch starts :");
        for (Object o: a) {
            //print(o);
            boolean notfound = true;
            if (o.getClass().isArray()) {

                String type = o.getClass().getName().toString();
                //print("type is "+type);
                switch (type) {
                    case "[I":
                        {
                            int[] test = (int[]) o;
                            print(i + " " + Arrays.toString(test));
                            break;
                        }
                    case "[[I":
                        {
                            int[][] obj = (int[][]) o;

                            print(i + " " + Arrays.deepToString(obj));
                            break;
                        }
                    case "[J":
                        {

                            long[] obj = (long[]) o;
                            print(i + " " + Arrays.toString(obj));
                            break;
                        }
                    case "[[J":
                        {

                            long[][] obj = (long[][]) o;
                            print(i + " " + Arrays.deepToString(obj));
                            break;
                        }
                    case "[D":
                        {

                            double[] obj = (double[]) o;
                            print(i + " " + Arrays.toString(obj));
                            break;
                        }
                    case "[[D":
                        {

                            double[][] obj = (double[][]) o;
                            print(i + " " + Arrays.deepToString(obj));
                            break;
                        }
                    case "[Ljava.lang.String":
                        {

                            String[] obj = (String[]) o;
                            print(i + " " + Arrays.toString(obj));
                            break;
                        }
                    case "[[Ljava.lang.String":
                        {

                            String[][] obj = (String[][]) o;
                            print(i + " " + Arrays.deepToString(obj));
                            break;
                        }
                    case "[C":
                        {
                            char[] obj = (char[]) o;
                            print(i + " " + Arrays.toString(obj));
                            break;
                        }
                    case "[[C":
                        {

                            char[][] obj = (char[][]) o;
                            print(i + " " + Arrays.deepToString(obj));
                            break;
                        }

                    default:
                        {
                            print(i + " type not identified");
                            break;
                        }
                }
                notfound = false;

            }
            if (o.getClass() == ArrayList.class) {
                print(i + " al: " + o);
                notfound = false;
            }
            if (o.getClass() == HashSet.class) {
                print(i + " hs: " + o);
                notfound = false;
            }
            if (o.getClass() == TreeSet.class) {
                print(i + " ts: " + o);
                notfound = false;
            }
            if (o.getClass() == TreeMap.class) {
                print(i + " tm: " + o);
                notfound = false;
            }
            if (o.getClass() == HashMap.class) {
                print(i + " hm: " + o);
                notfound = false;
            }
            if (o.getClass() == LinkedList.class) {
                print(i + " ll: " + o);
                notfound = false;
            }
            if (o.getClass() == PriorityQueue.class) {
                print(i + " pq : " + o);
                notfound = false;
            }
            if (o.getClass() == pair.class) {
                print(i + " pq : " + o);
                notfound = false;
            }

            if (notfound) {
                print(i + " unknown: " + o);
            }
            i++;
        }
        print("watch ends ");
    }

}


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

public class Main {
    public static void main(String[] args) {
        InputReader in = new InputReader(System.in);
        PrintWriter w = new PrintWriter(System.out);
        char[] s = in.readString().toCharArray();
        char[] t = in.readString().toCharArray();
        int cnt = 0;
        for (int i = 0; i < s.length; i++) {
            if (s[i] != t[i])
                cnt++;
        }
        w.println(cnt);
        w.close();
    }

    static class InputReader {

        private final InputStream stream;
        private final byte[] buf = new byte[8192];
        private int curChar, snumChars;
        private SpaceCharFilter filter;

        public InputReader(InputStream stream) {
            this.stream = stream;
        }

        public int snext() {
            if (snumChars == -1)
                throw new InputMismatchException();
            if (curChar >= snumChars) {
                curChar = 0;
                try {
                    snumChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (snumChars <= 0)
                    return -1;
            }
            return buf[curChar++];
        }

        public int nextInt() {
            int c = snext();
            while (isSpaceChar(c)) {
                c = snext();
            }
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = snext();
            }
            int res = 0;
            do {
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = snext();
            } while (!isSpaceChar(c));
            return res * sgn;
        }

        public long nextLong() {
            int c = snext();
            while (isSpaceChar(c)) {
                c = snext();
            }
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = snext();
            }
            long res = 0;
            do {
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = snext();
            } while (!isSpaceChar(c));
            return res * sgn;
        }

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

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

        public String readString() {
            int c = snext();
            while (isSpaceChar(c)) {
                c = snext();
            }
            StringBuilder res = new StringBuilder();
            do {
                res.appendCodePoint(c);
                c = snext();
            } while (!isSpaceChar(c));
            return res.toString();
        }

        public String nextLine() {
            int c = snext();
            while (isSpaceChar(c))
                c = snext();
            StringBuilder res = new StringBuilder();
            do {
                res.appendCodePoint(c);
                c = snext();
            } while (!isEndOfLine(c));
            return res.toString();
        }

        public boolean isSpaceChar(int c) {
            if (filter != null)
                return filter.isSpaceChar(c);
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        private boolean isEndOfLine(int c) {
            return c == '\n' || c == '\r' || c == -1;
        }

        public interface SpaceCharFilter {
            public boolean isSpaceChar(int ch);
        }
    }
}


import java.util.Scanner;

public class Main {
	public static void main(String args[]) {
		Scanner stdIn = new Scanner(System.in);
		char[] S = stdIn.next().toCharArray();
		char[] T = stdIn.next().toCharArray();

		int cnt = 0;

		for(int i = 0; i < S.length; i ++) {
			if(S[i] != T[i]) {
				cnt ++;
			}
		}

		if(cnt == S.length) {
			System.out.println(cnt);
		}else {
			System.out.println((int) Math.min(cnt, S.length - cnt));
		}
	}
}


import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc = new Scanner(System.in);
		String[] s = sc.next().split("");
		String[] t = sc.nextLine().split("");
		int ans = 0;
		for (int i = 0; i < s.length; i++) {
			if (!s[i].equals(t[i])) {
				ans++;
			}
		}
		System.out.println(ans);
	}

}


public class Main {
  public static void main(String[] args) {
    String S = new java.util.Scanner(System.in).nextLine();
    String T = new java.util.Scanner(System.in).nextLine();
    int num = S.length();
    int counts = 0;
    for (int i = 0; i < num; i++) {
      if (S.charAt(i) != T.charAt(i)) {
        counts++;
      }
    }
    System.out.println(counts);
  }
}


#include <bits/stdc++.h>

using namespace std;

#define all(x) (x).begin(), (x).end()

typedef long long ll;

void solve(){
	string s, t;
	cin >> s >> t;
	int ctn = 0;
	for(auto i = 0; i < s.size(); ++i) {
		if(s[i] != t[i]) ++ctn;
	}
	cout << ctn << "\n";
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

	solve();

    return 0;
}


#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pb push_back
#define mp make_pair
#define mt make_tuple
#define ff first
#define ss second
#define pii pair <int,int>
#define pll pair <ll,ll>
#define testcase() int t; cin>>t; while(t--)
#define forn(i,n) for(int i=0;i<n;i++)
#define forn1(i,n) for(int i=1;i<=n;i++)
#define vll vector <ll>
#define all(v) v.begin(),v.end()

ll M = 1e9 + 7;
double pi = acos(-1.0);
ll powerm(ll x,ll y){ ll res=1; while(y){ if(y&1) res=(res*x)%M; y=y>>1; x=(x*x)%M;} return res%M; }
ll power(ll x,ll y){ ll res=1; while(y){ if(y&1) res=(res*x); y=y>>1; x=(x*x);} return res; }
ll gcd(ll a,ll b){if(b>a)return gcd(b,a); if(b==0)return a; return gcd(b,a%b);}

int main() {

	//ifstream cin("input.txt");
	//ofstream cout("output.txt");
	ios_base::sync_with_stdio(false);
    cin.tie(NULL);

	string s,t; cin>>s>>t;
	int l = s.length();
	int c = 0;
	forn(i,l)
	{
		if(s[i]!=t[i]) c++;
	}
	cout<<c;
	return 0;
}


#include <bits/stdc++.h>
#include <cassert>
#define rep(i, n) for (int i = 0; i < (n); i++)
using namespace std;
using ll = long long;
using P = pair<int, int>;
struct Edge
{
  int to;
  int weight;
  Edge(int t, int w) : to(t), weight(w) {}
};
using Graph = vector<vector<Edge>>;
// using Graph = vector<vector<int>>;

const long long INF = 1LL << 60;
const int INT_INF = 1000000000;

int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
// int dx[8] = {-1, -1, -1, 0, 0, 1, 1, 1}, dy[8] = {-1, 0, 1, 1, -1, 1, 0, -1};

int main()
{
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  string S, T;
  cin >> S >> T;
  ll ans = 0;
  for (int i = 0; i < S.size(); i++)
    if (S[i] != T[i])
      ans++;
  cout << ans << endl;
  return 0;
}


#include <bits/stdc++.h>
using namespace std;
#define rep(i, ss, ee) for (int i = (ss); i < (ee); ++i)

string s, t;
void input() { cin >> s >> t; }
void solve() {
  int ans;
  rep(i, 0, s.size()) if (s[i] != t[i]) ans++;
  cout << ans << endl;
}

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


#include <bits/stdc++.h>
using namespace std;
#define rep(i, ss, ee) for (int i = (ss); i < (ee); ++i)

string s, t;
void input() { cin >> s >> t; }
void solve() {
  int ans;
  rep(i, 0, s.size()) { ans += int(s[i] != t[i]); }
  cout << ans << endl;
}

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


#include <bits/stdc++.h>
using namespace std;
#define rep(i, ss, ee) for (int i = (ss); i < (ee); ++i)

string s, t;
void input() { cin >> s >> t; }
void solve() {
  int ans;
  rep(i, 0, s.size()) { ans += (s[i] != t[i]); }
  cout << ans << endl;
}

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


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

int main(void)
{
  int n = 0, min = 0;
  char s[200002], t[200002];
  fgets(s, 200002, stdin);
  fgets(t, 200002, stdin);

  while (s[n] != '\0')
  {
    n++;
  }

  for (int i = 0; i < n - 1; i++)
  {
    if (s[i] != t[i])
    {
      min++;
    }
  }

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


#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <math.h>
#include <limits.h>
int main(){
    int i,ans=0,stln;
    char s[200020]={},t[200020]={};
    scanf("%s %s",s,t);
    stln=strlen(s);
    for(i=0; i<stln; i++){
        if(s[i]!=t[i])ans++;
    }
    printf("%d",ans);
    return 0;
}


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

#define STRLEN_MAX 200001

int	main(void)
{
  char	*s;
  char	*t;
  int	diff;
  int	i;

  i = 0;
  s = (char *)malloc(STRLEN_MAX * sizeof(char));
  t = (char *)malloc(STRLEN_MAX * sizeof(char));
  while(i < STRLEN_MAX)
  {
    s[i] = '\0';
    t[i] = '\0';
    i++;
  }
  scanf("%s", s);
  scanf("%s", t);
  i = 0;
  diff = 0;
  while (s[i] != '\0')
  {
    if (s[i] != t[i])
      diff++;
    i++;
  }
  free(s);
  free(t);
  printf("%d\n", diff);
  return (0);
}


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

    char S[200001],T[200001];
    int count,i,len;
    scanf("%s %s",S,T);

    len = strlen(S);
    for(i=0; i<=len; i++){
        if(S[i] != T[i]){
            count++;
        }
    }

    printf("%d\n",count);

    return 0;
}


# include <iostream>
# include <string>
using namespace std;

int main() {
    string s, t;
    cin >> s >> t;
    int ans = 0;
    for (int i = 0; i < (int)s.size(); i++) {
        if (s[i] != t[i]) ans++;
    }
    cout << ans << endl;
    return 0;
}


#include <stdio.h>
#include <string.h>
#define maxn 200000
char s[maxn],t[maxn];
int main(){
	int i,n,cnt=0;
	scanf("%s%s",s,t);
	n=strlen(s);
	for(i=0;i<n;i++)
		if(s[i]!=t[i])cnt++;
	printf("%d\n",cnt);
	return 0;
}


fs = require('fs');
input = fs.readFileSync('/dev/stdin','utf8');
S = input.split('\n')[0];
T = input.split('\n')[1];
R = 0;
for(i = 0; i < S.length; i++) {
  if(S[i] != T[i]) R = R + 1;
}
console.log(R);


let input = require("fs").readFileSync("/dev/stdin", "utf8")

function main() {
    const [S,T] = load(2,1,String)

    let result = 0
    for(let i = 0; i < S.length; i++) {
        if(S[i] !== T[i]) {
            result++
        }
    }

    return result
}

/*

入力値を読み込む
load(rows = 1, cols = 1, type = Number)

TruthyならYes, FalsyならNo
yesno(boolean) => String

数列の和
array_sum(numbers) => Number

対無限ループ安全装置
inifinite_loop_preventer(max = 1e5)

配列の中から最大値を返す
array_max(numbers, initial_value = null) => Number

配列の中から最小値を返す
array_min(numbers, initial_value = null) => Number

オブジェクトのスナップショットをconsole.logする
log_obj(value)

nを素因数分解
math_prime_factors(n) => { 素数: n乗 }

2次元配列を作る
new_array_2d(x_len, y_len = 0, init_value = 0) => [[]]

最大公約数
gcd(a, b) => Number

最小公倍数
lcm(a,b) => Number

subsetはsetの部分集合である
check_if_superset(set, subset) => Boolean

和集合
set_union(a, b) => Set

積集合
set_intersection(a, b) => Set

対称差集合
set_symmetric_difference(a, b) => Set

差集合
set_difference(a, b) => Set

配列からc個取る組み合わせ全列挙
set_combinations(array, count) => [[]]

*/

// console.time()
let inputs = input.split(/[\s\n]/)
let inifinite_loop_prevent_counter = 0
let result = main()
if(result === undefined) {
    console.warn("result is undefined")
} else {
    console.log(result)
}
// console.timeEnd()

// 入力値を読み込む
function load(rows = 1, cols = 1, type = Number) {
    const length = rows * cols
    let result = inputs.splice(0, length)

    if(type !== String) result = result.map(type)
    if(cols > 1) {
        const arrays = new Array(cols)
        for(let col = 0; col < cols; col++) {
            arrays[col] = new Array()
            for(let row = 0; row < rows; row++) {
                arrays[col].push(result[row * cols + col])
            }
        }
        result = arrays
    }

    return result
}

// TruthyならYes, FalsyならNo
function yesno(value) {
    return value ? 'Yes' : 'No'
}

// 数列の和
function array_sum(numbers) {
    return numbers.reduce((acc, cur) => acc + cur, 0)
}

// 対無限ループ安全装置
function inifinite_loop_preventer(max = 1e5) {
    inifinite_loop_prevent_counter++
    if(inifinite_loop_prevent_counter >= max) {
        throw new Error("Infinite loop")
    }
}

// 配列の中から最大値を返す
function array_max(numbers, initial_value = null) {
    let result = (initial_value === null) ? numbers[0] : initial_value
    for(const n of numbers) if(n > result) result = n
    return result
}

// 配列の中から最小値を返す
function array_min(numbers, initial_value = null) {
    let result = (initial_value === null) ? numbers[0] : initial_value
    for(const n of numbers) if(n < result) result = n
    return result
}

// オブジェクトのスナップショットをconsole.logする
function log_obj(value) {
    console.log(JSON.parse(JSON.stringify(value)))
}

// 素因数分解 { 素数: n乗 }
function math_prime_factors(n) {
    const result = {}

    for(let i = 2; i * i <= n; i++) {
        if(n % i === 0) {
            n /= i
            result[i] = 1

            while(n % i === 0) {
                n /= i
                result[i]++
            }
        }
    }

    if(n > 1) result[n] = 1

    return result
}

// 2次元配列を作る
function new_array_2d(x_len, y_len = 0, init_value = 0) {

    const array = new Array()
    for(let i = 0; i < x_len; i++) {
        const y = y_len ? new Array(y_len).fill(init_value) : new Array()
        array.push(y)
    }

    return array
}

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

// 最小公倍数
function lcm(a,b) {
    const g = (n, m) => m ? g(m, n % m) : n
    return a * b / g(a, b)
}

// subsetはsetの部分集合である
function check_if_superset(set, subset) {
    for(let el of subset) {
        if(!set.has(el)) {
            return false
        }
    }
    return true
}

// 和集合
function set_union(a, b) {
    const result = new Set(a)
    for(const el of b) result.add(el)
    return result
}

// 積集合
function set_intersection(a, b) {
    let result = new Set()
    for(let el of b) {
        if(a.has(el)) {
            result.add(el)
        }
    }
    return result
}

// 対称差集合
function set_symmetric_difference(a, b) {
    let result = new Set(a)
    for(let el of b) {
        if(result.has(el)) {
            result.delete(el)
        } else {
            result.add(el)
        }
    }
    return result
}

// 差集合
function set_difference(a, b) {
    let result = new Set(a)
    for(let el of b) result.delete(el)
    return result
}

// 配列からc個取る組み合わせ全列挙
function set_combinations(array, count) {

    const result = []

    function _combi({ pre = [], rest }) {

        if(pre.length + rest.length < count) return

        if(pre.length < count) {
            for(let i = 0; i < rest.length; i++) {
                _combi({
                    pre: [...pre, rest[i]],
                    rest: rest.slice(0,i)
                })
            }
        } else {
            result.push(pre)
        }
    }

    _combi({ rest: array })

    return result
}

function math_permutation(n, r) {
    let res = 1
    for(let i = 0; i < r; i++) {
        res *= n - i
    }
    return res
}

function math_combination(n, r) {
    return math_permutation(n, r) / math_permutation(r, r)
}


'use strict';
function Main(stdin){
  const input = stdin.trim().split(/\r?\n/g);
  const S = input[0];
  const T = input[1];
  let count = 0;
  for(let i = 0; i < S.length; i++){
    if(S.charAt(i) !== T.charAt(i)) count++;
  }
  console.log(count);
}

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


function Main (input) {
    input = input.split("\n");
    // var z = parseInt(input[0], 10);

    var s = input[0]
    var t = input[1]
    var z = []

    var cnt = 0
    var i = 0
    s.split("").forEach(char_s => {
        var char_t = t.split("")[i]

        if (char_s !== char_t) {
            cnt++
            z.push(char_t)
        } else {
            z.push(char_s)
        }

        var y = z.join("")

        if (t === y) {
            return
        }

        i++
    })

    console.log(cnt)
}

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


process.stdin.setEncoding('utf-8');
process.stdin.on('data', async (data) => {
    const array = await data.trim().split(/\n/);
    const res = await hoge(array);
    console.log(res)
});
const hoge = (array) => {
    let res = 0;
    for (let i = 0; i < array[0].trim().length; i++) {
        if (array[0][i] !== array[1][i]){
            res ++
        }
    }
    return res;
};


process.stdin.setEncoding('utf-8');
process.stdin.on('data', async (data) => {
    const array = data.trim().split(/\n/);
    const res = await hoge(array);
    console.log(res)
});
const hoge = (array) => {
    let res = 0;
    for (let i = 0; i < array[0].trim().length; i++) {
        if (array[0][i] !== array[1][i]){
            res ++
        }
    }
    return res;
};


package main

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

var (
	scanner  *bufio.Scanner
	byWord   bool   //flag for tokenization
	eof      bool   //flag of end-of-file
	splitter string //delimiter for Ints(), etc.
)

func main() {
	s := Line()
	t := Line()
	ans := 0
	for i := 0; i < len(s); i++ {
		if s[i] != t[i] {
			ans++
		}
	}
	fmt.Println(ans)
}

func init() {
	scanner = bufio.NewScanner(os.Stdin)
	scanner.Buffer([]byte{}, math.MaxInt64)
	scanner.Split(scanWordsOrLines)
	eof = false
	splitter = " "
}

func scanWordsOrLines(data []byte, atEOF bool) (advance int, token []byte, err error) {
	if byWord {
		return bufio.ScanWords(data, atEOF)
	} else {
		return bufio.ScanLines(data, atEOF)
	}
}

func text(byword bool) string {
	byWord = byword
	if scanner.Scan() {
		return scanner.Text()
	}
	eof = true
	return ""
}

//basics
func EOF() bool {
	return eof
}

func Word() string {
	return text(true)
}

func Words() []string {
	return strings.Split(Line(), splitter)
}

func Line() string {
	return text(false)
}

func Lines() []string {
	var ret []string
	for {
		l := Line()
		if EOF() {
			break
		}
		ret = append(ret, l)
	}
	return ret
}

func Byte() byte {
	return byte(Uint8())
}

//auto-generated code
func Int() int {
	ret, _ := strconv.ParseInt(Word(), 10, 0)
	return int(ret)
}

func Ints() []int {
	words := Words()
	n := len(words)
	ret := make([]int, n)
	for i := 0; i < n; i++ {
		v, _ := strconv.ParseInt(words[i], 10, 0)
		ret[i] = int(v)
	}
	return ret
}

func Ints2() (int, int) {
	return Int(), Int()
}

func Ints3() (int, int, int) {
	return Int(), Int(), Int()
}

func Ints4() (int, int, int, int) {
	return Int(), Int(), Int(), Int()
}

func Ints5() (int, int, int, int, int) {
	return Int(), Int(), Int(), Int(), Int()
}

func Ints6() (int, int, int, int, int, int) {
	return Int(), Int(), Int(), Int(), Int(), Int()
}

func Ints7() (int, int, int, int, int, int, int) {
	return Int(), Int(), Int(), Int(), Int(), Int(), Int()
}

func Ints8() (int, int, int, int, int, int, int, int) {
	return Int(), Int(), Int(), Int(), Int(), Int(), Int(), Int()
}

func Ints9() (int, int, int, int, int, int, int, int, int) {
	return Int(), Int(), Int(), Int(), Int(), Int(), Int(), Int(), Int()
}

func IntsN(n int) []int {
	ret := make([]int, n)
	for i := 0; i < n; i++ {
		ret[i] = Int()
	}
	return ret
}

func Int8() int8 {
	ret, _ := strconv.ParseInt(Word(), 10, 8)
	return int8(ret)
}

func Int8s() []int8 {
	words := Words()
	n := len(words)
	ret := make([]int8, n)
	for i := 0; i < n; i++ {
		v, _ := strconv.ParseInt(words[i], 10, 8)
		ret[i] = int8(v)
	}
	return ret
}

func Int8s2() (int8, int8) {
	return Int8(), Int8()
}

func Int8s3() (int8, int8, int8) {
	return Int8(), Int8(), Int8()
}

func Int8s4() (int8, int8, int8, int8) {
	return Int8(), Int8(), Int8(), Int8()
}

func Int8s5() (int8, int8, int8, int8, int8) {
	return Int8(), Int8(), Int8(), Int8(), Int8()
}

func Int8s6() (int8, int8, int8, int8, int8, int8) {
	return Int8(), Int8(), Int8(), Int8(), Int8(), Int8()
}

func Int8s7() (int8, int8, int8, int8, int8, int8, int8) {
	return Int8(), Int8(), Int8(), Int8(), Int8(), Int8(), Int8()
}

func Int8s8() (int8, int8, int8, int8, int8, int8, int8, int8) {
	return Int8(), Int8(), Int8(), Int8(), Int8(), Int8(), Int8(), Int8()
}

func Int8s9() (int8, int8, int8, int8, int8, int8, int8, int8, int8) {
	return Int8(), Int8(), Int8(), Int8(), Int8(), Int8(), Int8(), Int8(), Int8()
}

func Int8sN(n int) []int8 {
	ret := make([]int8, n)
	for i := 0; i < n; i++ {
		ret[i] = Int8()
	}
	return ret
}

func Int16() int16 {
	ret, _ := strconv.ParseInt(Word(), 10, 16)
	return int16(ret)
}

func Int16s() []int16 {
	words := Words()
	n := len(words)
	ret := make([]int16, n)
	for i := 0; i < n; i++ {
		v, _ := strconv.ParseInt(words[i], 10, 16)
		ret[i] = int16(v)
	}
	return ret
}

func Int16s2() (int16, int16) {
	return Int16(), Int16()
}

func Int16s3() (int16, int16, int16) {
	return Int16(), Int16(), Int16()
}

func Int16s4() (int16, int16, int16, int16) {
	return Int16(), Int16(), Int16(), Int16()
}

func Int16s5() (int16, int16, int16, int16, int16) {
	return Int16(), Int16(), Int16(), Int16(), Int16()
}

func Int16s6() (int16, int16, int16, int16, int16, int16) {
	return Int16(), Int16(), Int16(), Int16(), Int16(), Int16()
}

func Int16s7() (int16, int16, int16, int16, int16, int16, int16) {
	return Int16(), Int16(), Int16(), Int16(), Int16(), Int16(), Int16()
}

func Int16s8() (int16, int16, int16, int16, int16, int16, int16, int16) {
	return Int16(), Int16(), Int16(), Int16(), Int16(), Int16(), Int16(), Int16()
}

func Int16s9() (int16, int16, int16, int16, int16, int16, int16, int16, int16) {
	return Int16(), Int16(), Int16(), Int16(), Int16(), Int16(), Int16(), Int16(), Int16()
}

func Int16sN(n int) []int16 {
	ret := make([]int16, n)
	for i := 0; i < n; i++ {
		ret[i] = Int16()
	}
	return ret
}

func Int32() int32 {
	ret, _ := strconv.ParseInt(Word(), 10, 32)
	return int32(ret)
}

func Int32s() []int32 {
	words := Words()
	n := len(words)
	ret := make([]int32, n)
	for i := 0; i < n; i++ {
		v, _ := strconv.ParseInt(words[i], 10, 32)
		ret[i] = int32(v)
	}
	return ret
}

func Int32s2() (int32, int32) {
	return Int32(), Int32()
}

func Int32s3() (int32, int32, int32) {
	return Int32(), Int32(), Int32()
}

func Int32s4() (int32, int32, int32, int32) {
	return Int32(), Int32(), Int32(), Int32()
}

func Int32s5() (int32, int32, int32, int32, int32) {
	return Int32(), Int32(), Int32(), Int32(), Int32()
}

func Int32s6() (int32, int32, int32, int32, int32, int32) {
	return Int32(), Int32(), Int32(), Int32(), Int32(), Int32()
}

func Int32s7() (int32, int32, int32, int32, int32, int32, int32) {
	return Int32(), Int32(), Int32(), Int32(), Int32(), Int32(), Int32()
}

func Int32s8() (int32, int32, int32, int32, int32, int32, int32, int32) {
	return Int32(), Int32(), Int32(), Int32(), Int32(), Int32(), Int32(), Int32()
}

func Int32s9() (int32, int32, int32, int32, int32, int32, int32, int32, int32) {
	return Int32(), Int32(), Int32(), Int32(), Int32(), Int32(), Int32(), Int32(), Int32()
}

func Int32sN(n int) []int32 {
	ret := make([]int32, n)
	for i := 0; i < n; i++ {
		ret[i] = Int32()
	}
	return ret
}

func Int64() int64 {
	ret, _ := strconv.ParseInt(Word(), 10, 64)
	return int64(ret)
}

func Int64s() []int64 {
	words := Words()
	n := len(words)
	ret := make([]int64, n)
	for i := 0; i < n; i++ {
		v, _ := strconv.ParseInt(words[i], 10, 64)
		ret[i] = int64(v)
	}
	return ret
}

func Int64s2() (int64, int64) {
	return Int64(), Int64()
}

func Int64s3() (int64, int64, int64) {
	return Int64(), Int64(), Int64()
}

func Int64s4() (int64, int64, int64, int64) {
	return Int64(), Int64(), Int64(), Int64()
}

func Int64s5() (int64, int64, int64, int64, int64) {
	return Int64(), Int64(), Int64(), Int64(), Int64()
}

func Int64s6() (int64, int64, int64, int64, int64, int64) {
	return Int64(), Int64(), Int64(), Int64(), Int64(), Int64()
}

func Int64s7() (int64, int64, int64, int64, int64, int64, int64) {
	return Int64(), Int64(), Int64(), Int64(), Int64(), Int64(), Int64()
}

func Int64s8() (int64, int64, int64, int64, int64, int64, int64, int64) {
	return Int64(), Int64(), Int64(), Int64(), Int64(), Int64(), Int64(), Int64()
}

func Int64s9() (int64, int64, int64, int64, int64, int64, int64, int64, int64) {
	return Int64(), Int64(), Int64(), Int64(), Int64(), Int64(), Int64(), Int64(), Int64()
}

func Int64sN(n int) []int64 {
	ret := make([]int64, n)
	for i := 0; i < n; i++ {
		ret[i] = Int64()
	}
	return ret
}

func Uint() uint {
	ret, _ := strconv.ParseUint(Word(), 10, 0)
	return uint(ret)
}

func Uints() []uint {
	words := Words()
	n := len(words)
	ret := make([]uint, n)
	for i := 0; i < n; i++ {
		v, _ := strconv.ParseUint(words[i], 10, 0)
		ret[i] = uint(v)
	}
	return ret
}

func Uints2() (uint, uint) {
	return Uint(), Uint()
}

func Uints3() (uint, uint, uint) {
	return Uint(), Uint(), Uint()
}

func Uints4() (uint, uint, uint, uint) {
	return Uint(), Uint(), Uint(), Uint()
}

func Uints5() (uint, uint, uint, uint, uint) {
	return Uint(), Uint(), Uint(), Uint(), Uint()
}

func Uints6() (uint, uint, uint, uint, uint, uint) {
	return Uint(), Uint(), Uint(), Uint(), Uint(), Uint()
}

func Uints7() (uint, uint, uint, uint, uint, uint, uint) {
	return Uint(), Uint(), Uint(), Uint(), Uint(), Uint(), Uint()
}

func Uints8() (uint, uint, uint, uint, uint, uint, uint, uint) {
	return Uint(), Uint(), Uint(), Uint(), Uint(), Uint(), Uint(), Uint()
}

func Uints9() (uint, uint, uint, uint, uint, uint, uint, uint, uint) {
	return Uint(), Uint(), Uint(), Uint(), Uint(), Uint(), Uint(), Uint(), Uint()
}

func UintsN(n int) []uint {
	ret := make([]uint, n)
	for i := 0; i < n; i++ {
		ret[i] = Uint()
	}
	return ret
}

func Uint8() uint8 {
	ret, _ := strconv.ParseUint(Word(), 10, 8)
	return uint8(ret)
}

func Uint8s() []uint8 {
	words := Words()
	n := len(words)
	ret := make([]uint8, n)
	for i := 0; i < n; i++ {
		v, _ := strconv.ParseUint(words[i], 10, 8)
		ret[i] = uint8(v)
	}
	return ret
}

func Uint8s2() (uint8, uint8) {
	return Uint8(), Uint8()
}

func Uint8s3() (uint8, uint8, uint8) {
	return Uint8(), Uint8(), Uint8()
}

func Uint8s4() (uint8, uint8, uint8, uint8) {
	return Uint8(), Uint8(), Uint8(), Uint8()
}

func Uint8s5() (uint8, uint8, uint8, uint8, uint8) {
	return Uint8(), Uint8(), Uint8(), Uint8(), Uint8()
}

func Uint8s6() (uint8, uint8, uint8, uint8, uint8, uint8) {
	return Uint8(), Uint8(), Uint8(), Uint8(), Uint8(), Uint8()
}

func Uint8s7() (uint8, uint8, uint8, uint8, uint8, uint8, uint8) {
	return Uint8(), Uint8(), Uint8(), Uint8(), Uint8(), Uint8(), Uint8()
}

func Uint8s8() (uint8, uint8, uint8, uint8, uint8, uint8, uint8, uint8) {
	return Uint8(), Uint8(), Uint8(), Uint8(), Uint8(), Uint8(), Uint8(), Uint8()
}

func Uint8s9() (uint8, uint8, uint8, uint8, uint8, uint8, uint8, uint8, uint8) {
	return Uint8(), Uint8(), Uint8(), Uint8(), Uint8(), Uint8(), Uint8(), Uint8(), Uint8()
}

func Uint8sN(n int) []uint8 {
	ret := make([]uint8, n)
	for i := 0; i < n; i++ {
		ret[i] = Uint8()
	}
	return ret
}

func Uint16() uint16 {
	ret, _ := strconv.ParseUint(Word(), 10, 16)
	return uint16(ret)
}

func Uint16s() []uint16 {
	words := Words()
	n := len(words)
	ret := make([]uint16, n)
	for i := 0; i < n; i++ {
		v, _ := strconv.ParseUint(words[i], 10, 16)
		ret[i] = uint16(v)
	}
	return ret
}

func Uint16s2() (uint16, uint16) {
	return Uint16(), Uint16()
}

func Uint16s3() (uint16, uint16, uint16) {
	return Uint16(), Uint16(), Uint16()
}

func Uint16s4() (uint16, uint16, uint16, uint16) {
	return Uint16(), Uint16(), Uint16(), Uint16()
}

func Uint16s5() (uint16, uint16, uint16, uint16, uint16) {
	return Uint16(), Uint16(), Uint16(), Uint16(), Uint16()
}

func Uint16s6() (uint16, uint16, uint16, uint16, uint16, uint16) {
	return Uint16(), Uint16(), Uint16(), Uint16(), Uint16(), Uint16()
}

func Uint16s7() (uint16, uint16, uint16, uint16, uint16, uint16, uint16) {
	return Uint16(), Uint16(), Uint16(), Uint16(), Uint16(), Uint16(), Uint16()
}

func Uint16s8() (uint16, uint16, uint16, uint16, uint16, uint16, uint16, uint16) {
	return Uint16(), Uint16(), Uint16(), Uint16(), Uint16(), Uint16(), Uint16(), Uint16()
}

func Uint16s9() (uint16, uint16, uint16, uint16, uint16, uint16, uint16, uint16, uint16) {
	return Uint16(), Uint16(), Uint16(), Uint16(), Uint16(), Uint16(), Uint16(), Uint16(), Uint16()
}

func Uint16sN(n int) []uint16 {
	ret := make([]uint16, n)
	for i := 0; i < n; i++ {
		ret[i] = Uint16()
	}
	return ret
}

func Uint32() uint32 {
	ret, _ := strconv.ParseUint(Word(), 10, 32)
	return uint32(ret)
}

func Uint32s() []uint32 {
	words := Words()
	n := len(words)
	ret := make([]uint32, n)
	for i := 0; i < n; i++ {
		v, _ := strconv.ParseUint(words[i], 10, 32)
		ret[i] = uint32(v)
	}
	return ret
}

func Uint32s2() (uint32, uint32) {
	return Uint32(), Uint32()
}

func Uint32s3() (uint32, uint32, uint32) {
	return Uint32(), Uint32(), Uint32()
}

func Uint32s4() (uint32, uint32, uint32, uint32) {
	return Uint32(), Uint32(), Uint32(), Uint32()
}

func Uint32s5() (uint32, uint32, uint32, uint32, uint32) {
	return Uint32(), Uint32(), Uint32(), Uint32(), Uint32()
}

func Uint32s6() (uint32, uint32, uint32, uint32, uint32, uint32) {
	return Uint32(), Uint32(), Uint32(), Uint32(), Uint32(), Uint32()
}

func Uint32s7() (uint32, uint32, uint32, uint32, uint32, uint32, uint32) {
	return Uint32(), Uint32(), Uint32(), Uint32(), Uint32(), Uint32(), Uint32()
}

func Uint32s8() (uint32, uint32, uint32, uint32, uint32, uint32, uint32, uint32) {
	return Uint32(), Uint32(), Uint32(), Uint32(), Uint32(), Uint32(), Uint32(), Uint32()
}

func Uint32s9() (uint32, uint32, uint32, uint32, uint32, uint32, uint32, uint32, uint32) {
	return Uint32(), Uint32(), Uint32(), Uint32(), Uint32(), Uint32(), Uint32(), Uint32(), Uint32()
}

func Uint32sN(n int) []uint32 {
	ret := make([]uint32, n)
	for i := 0; i < n; i++ {
		ret[i] = Uint32()
	}
	return ret
}

func Uint64() uint64 {
	ret, _ := strconv.ParseUint(Word(), 10, 64)
	return uint64(ret)
}

func Uint64s() []uint64 {
	words := Words()
	n := len(words)
	ret := make([]uint64, n)
	for i := 0; i < n; i++ {
		v, _ := strconv.ParseUint(words[i], 10, 64)
		ret[i] = uint64(v)
	}
	return ret
}

func Uint64s2() (uint64, uint64) {
	return Uint64(), Uint64()
}

func Uint64s3() (uint64, uint64, uint64) {
	return Uint64(), Uint64(), Uint64()
}

func Uint64s4() (uint64, uint64, uint64, uint64) {
	return Uint64(), Uint64(), Uint64(), Uint64()
}

func Uint64s5() (uint64, uint64, uint64, uint64, uint64) {
	return Uint64(), Uint64(), Uint64(), Uint64(), Uint64()
}

func Uint64s6() (uint64, uint64, uint64, uint64, uint64, uint64) {
	return Uint64(), Uint64(), Uint64(), Uint64(), Uint64(), Uint64()
}

func Uint64s7() (uint64, uint64, uint64, uint64, uint64, uint64, uint64) {
	return Uint64(), Uint64(), Uint64(), Uint64(), Uint64(), Uint64(), Uint64()
}

func Uint64s8() (uint64, uint64, uint64, uint64, uint64, uint64, uint64, uint64) {
	return Uint64(), Uint64(), Uint64(), Uint64(), Uint64(), Uint64(), Uint64(), Uint64()
}

func Uint64s9() (uint64, uint64, uint64, uint64, uint64, uint64, uint64, uint64, uint64) {
	return Uint64(), Uint64(), Uint64(), Uint64(), Uint64(), Uint64(), Uint64(), Uint64(), Uint64()
}

func Uint64sN(n int) []uint64 {
	ret := make([]uint64, n)
	for i := 0; i < n; i++ {
		ret[i] = Uint64()
	}
	return ret
}

func Float32() float32 {
	ret, _ := strconv.ParseFloat(Word(), 32)
	return float32(ret)
}

func Float32s() []float32 {
	words := Words()
	n := len(words)
	ret := make([]float32, n)
	for i := 0; i < n; i++ {
		v, _ := strconv.ParseFloat(words[i], 32)
		ret[i] = float32(v)
	}
	return ret
}

func Float32s2() (float32, float32) {
	return Float32(), Float32()
}

func Float32s3() (float32, float32, float32) {
	return Float32(), Float32(), Float32()
}

func Float32s4() (float32, float32, float32, float32) {
	return Float32(), Float32(), Float32(), Float32()
}

func Float32s5() (float32, float32, float32, float32, float32) {
	return Float32(), Float32(), Float32(), Float32(), Float32()
}

func Float32s6() (float32, float32, float32, float32, float32, float32) {
	return Float32(), Float32(), Float32(), Float32(), Float32(), Float32()
}

func Float32s7() (float32, float32, float32, float32, float32, float32, float32) {
	return Float32(), Float32(), Float32(), Float32(), Float32(), Float32(), Float32()
}

func Float32s8() (float32, float32, float32, float32, float32, float32, float32, float32) {
	return Float32(), Float32(), Float32(), Float32(), Float32(), Float32(), Float32(), Float32()
}

func Float32s9() (float32, float32, float32, float32, float32, float32, float32, float32, float32) {
	return Float32(), Float32(), Float32(), Float32(), Float32(), Float32(), Float32(), Float32(), Float32()
}

func Float32sN(n int) []float32 {
	ret := make([]float32, n)
	for i := 0; i < n; i++ {
		ret[i] = Float32()
	}
	return ret
}

func Float64() float64 {
	ret, _ := strconv.ParseFloat(Word(), 64)
	return float64(ret)
}

func Float64s() []float64 {
	words := Words()
	n := len(words)
	ret := make([]float64, n)
	for i := 0; i < n; i++ {
		v, _ := strconv.ParseFloat(words[i], 64)
		ret[i] = float64(v)
	}
	return ret
}

func Float64s2() (float64, float64) {
	return Float64(), Float64()
}

func Float64s3() (float64, float64, float64) {
	return Float64(), Float64(), Float64()
}

func Float64s4() (float64, float64, float64, float64) {
	return Float64(), Float64(), Float64(), Float64()
}

func Float64s5() (float64, float64, float64, float64, float64) {
	return Float64(), Float64(), Float64(), Float64(), Float64()
}

func Float64s6() (float64, float64, float64, float64, float64, float64) {
	return Float64(), Float64(), Float64(), Float64(), Float64(), Float64()
}

func Float64s7() (float64, float64, float64, float64, float64, float64, float64) {
	return Float64(), Float64(), Float64(), Float64(), Float64(), Float64(), Float64()
}

func Float64s8() (float64, float64, float64, float64, float64, float64, float64, float64) {
	return Float64(), Float64(), Float64(), Float64(), Float64(), Float64(), Float64(), Float64()
}

func Float64s9() (float64, float64, float64, float64, float64, float64, float64, float64, float64) {
	return Float64(), Float64(), Float64(), Float64(), Float64(), Float64(), Float64(), Float64(), Float64()
}

func Float64sN(n int) []float64 {
	ret := make([]float64, n)
	for i := 0; i < n; i++ {
		ret[i] = Float64()
	}
	return ret
}

func Words2() (string, string) {
	return Word(), Word()
}

func Words3() (string, string, string) {
	return Word(), Word(), Word()
}

func Words4() (string, string, string, string) {
	return Word(), Word(), Word(), Word()
}

func Words5() (string, string, string, string, string) {
	return Word(), Word(), Word(), Word(), Word()
}

func Words6() (string, string, string, string, string, string) {
	return Word(), Word(), Word(), Word(), Word(), Word()
}

func Words7() (string, string, string, string, string, string, string) {
	return Word(), Word(), Word(), Word(), Word(), Word(), Word()
}

func Words8() (string, string, string, string, string, string, string, string) {
	return Word(), Word(), Word(), Word(), Word(), Word(), Word(), Word()
}

func Words9() (string, string, string, string, string, string, string, string, string) {
	return Word(), Word(), Word(), Word(), Word(), Word(), Word(), Word(), Word()
}

func WordsN(n int) []string {
	ret := make([]string, n)
	for i := 0; i < n; i++ {
		ret[i] = Word()
	}
	return ret
}

func Lines2() (string, string) {
	return Line(), Line()
}

func Lines3() (string, string, string) {
	return Line(), Line(), Line()
}

func Lines4() (string, string, string, string) {
	return Line(), Line(), Line(), Line()
}

func Lines5() (string, string, string, string, string) {
	return Line(), Line(), Line(), Line(), Line()
}

func Lines6() (string, string, string, string, string, string) {
	return Line(), Line(), Line(), Line(), Line(), Line()
}

func Lines7() (string, string, string, string, string, string, string) {
	return Line(), Line(), Line(), Line(), Line(), Line(), Line()
}

func Lines8() (string, string, string, string, string, string, string, string) {
	return Line(), Line(), Line(), Line(), Line(), Line(), Line(), Line()
}

func Lines9() (string, string, string, string, string, string, string, string, string) {
	return Line(), Line(), Line(), Line(), Line(), Line(), Line(), Line(), Line()
}

func LinesN(n int) []string {
	ret := make([]string, n)
	for i := 0; i < n; i++ {
		ret[i] = Line()
	}
	return ret
}

func Bytes2() (byte, byte) {
	return Byte(), Byte()
}

func Bytes3() (byte, byte, byte) {
	return Byte(), Byte(), Byte()
}

func Bytes4() (byte, byte, byte, byte) {
	return Byte(), Byte(), Byte(), Byte()
}

func Bytes5() (byte, byte, byte, byte, byte) {
	return Byte(), Byte(), Byte(), Byte(), Byte()
}

func Bytes6() (byte, byte, byte, byte, byte, byte) {
	return Byte(), Byte(), Byte(), Byte(), Byte(), Byte()
}

func Bytes7() (byte, byte, byte, byte, byte, byte, byte) {
	return Byte(), Byte(), Byte(), Byte(), Byte(), Byte(), Byte()
}

func Bytes8() (byte, byte, byte, byte, byte, byte, byte, byte) {
	return Byte(), Byte(), Byte(), Byte(), Byte(), Byte(), Byte(), Byte()
}

func Bytes9() (byte, byte, byte, byte, byte, byte, byte, byte, byte) {
	return Byte(), Byte(), Byte(), Byte(), Byte(), Byte(), Byte(), Byte(), Byte()
}

func BytesN(n int) []byte {
	ret := make([]byte, n)
	for i := 0; i < n; i++ {
		ret[i] = Byte()
	}
	return ret
}


    package main

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

    const (
    	initialBufSize = 1e4
    	maxBufSize     = 1e6 + 7
    )

    var buf []byte = make([]byte, maxBufSize)
    var sc = bufio.NewScanner(os.Stdin)

    func init() {
    	// sc.Split(bufio.ScanWords)
    	sc.Buffer(buf, maxBufSize)
    }

    func main() {
    	S, T := nextLine(), nextLine()
    	var ans int
    	for i := 0; i < len(S); i++ {
    		if S[i] != T[i] {
    			ans++
    		}
    	}
    	fmt.Println(ans)
    }

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


package main

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

var rdr = bufio.NewReaderSize(os.Stdin, 1000000)

func readLine() (ret string) {

	buf := make([]byte, 0, 1000000)
	for {
		l, p, e := rdr.ReadLine()
		if e != nil {
			return ""
		}
		buf = append(buf, l...)
		if !p {
			break
		}
	}
	return string(buf)
}

type Utls struct {
}

type uString string

var utls = &Utls{}

func (u *Utls) readLineU() uString {
	return uString(readLine())
}

func (u *Utls) atoi(str string) int {
	r, _ := strconv.Atoi(str)
	return r
}
func (u *Utls) itoa(n int) string {
	r := strconv.Itoa(n)
	return r
}
func (u uString) atoi() int {
	r, err := strconv.Atoi(string(u))
	if err != nil {
		return -1
	}
	return r
}
func (u uString) atoiArr() []int {
	ret := make([]int, 0)

	l := strings.Split(string(u), " ")

	for i := 0; i < len(l); i++ {
		s := (uString(l[i]))

		ret = append(ret, s.atoi())

	}
	return ret
}
func (u uString) String() string {
	return string(u)
}

func main() {
	 s:= readLine()
	 t:= readLine()
 		cnt:=0
	 for i,_:= range s {
		 if s[i] != t[i]{
			 cnt++
		 }
	 }
//	 r :=  (a)+ (a*a) + (a*a*a)
	 fmt.Println(cnt)
}


package main
import "fmt"
var S, T string
func max(a, b int) int {
  if a > b { return a }
  return b
}
func main() {
	fmt.Scanf("%s", &S)
	fmt.Scanf("%s", &T)
	m := len(S)
	dp := make([][]int, m+1)
	for i := range dp {
		dp[i] = make([]int, m+1)
	}

	for i:=1; i<m+1; i++ {
		for j:=1; j<m+1; j++ {
			if S[i-1] == T[j-1] {
				dp[i][j] = dp[i-1][j-1] + 1
			} else {
				dp[i][j] = max(dp[i][j-1], dp[i-1][j])
			}
		}
	}
	fmt.Println(len(S) - dp[m][m])
}


package main

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

var sc = bufio.NewScanner(os.Stdin)

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

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

func main() {

	var s, t string
	var cnt int
	sc.Split(bufio.ScanWords)
	s = newStr()
	t = newStr()

	for i := 0; i < len(s); i++ {
		if s[i] != t[i] {
			cnt++
		}
	}

	fmt.Println(cnt)
}


package main

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

func nextLine(r *bufio.Reader) string {
	var buf []byte
	for {
		line, isPrefix, err := r.ReadLine()
		if err != nil {
			panic(err)
		}
		buf = append(buf, line...)
		if !isPrefix {
			break
		}
	}
	return string(buf)
}

func nextStr(s *bufio.Scanner) string {
	s.Scan()
	ref := s.Bytes()
	cp := make([]byte, len(ref))
	copy(cp, ref)
	return string(cp)
}

func nextInt(s *bufio.Scanner) int {
	n, err := strconv.Atoi(nextStr(s))
	if err != nil {
		panic(err)
	}
	return n
}

func main() {
	// s := bufio.NewScanner(os.Stdin)
	// s.Split(bufio.ScanWords)
	r := bufio.NewReader(os.Stdin)

	S := nextLine(r)
	T := nextLine(r)

	ans := 1
	for i := 0; i < len(S); i++ {
		if S[i] != T[i] {
			ans++
		}
	}

	fmt.Println(ans)
}


def input_n
  gets.to_i               # 単一整数
end

def input_s
  gets.chomp              # 文字列。chompを付けないと改行文字がついてくる
end

def input_a
  gets.split.map(&:to_i)  # スペースで区切られた複数の整数
end

def input_o(num)
  num.times.map { gets.to_i }  # 縦に並んだ複数の整数。たまにある
end

def output_f(num)
  puts sprintf("%.12f", num)
end

s = input_s
t = input_s

cnt = 0
s.length.times do |i|
  cnt += 1 if s[i] == t[i]
end
puts s.length - cnt


str_a = gets
str_b = gets

str_length = str_a.length

same_character_num = 0
str_length.times do |i|
    if str_a[i] == str_b[i]
        same_character_num += 1
    end
end

result = str_length - same_character_num

puts result


s = gets.chomp
t = gets.chomp

c = 0
i = 0
while i < t.length
  if s[i] != t[i]
    c += 1
  end
  i += 1
end
print c


s = gets.chomp.chars
t = gets.chomp.chars
num = 0
for i in 1..s.length
     num = num + 1 if s[i] != t[i]
end
puts num


S=gets.chomp
T=gets.chomp
kekka=0
(0..S.size-1).each do |n|
  p S[n]
  kekka+=1 if S[n]!=T[n]
end
puts kekka


S=gets
T=gets
kekka=0
(0..S.size-1).each do |n|
  kekka+=1 if S[n]==T[n]
end
puts kekka


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

use proconio::input;

fn main() {
    input! {
        s: String,
        t: String,
    }

    let ans = s.chars().zip(t.chars()).filter(|&(a, b)| a != b).count();
    println!("{}", ans);
}


fn main() {
    let mut s = String::new();
    let mut t = String::new();

    std::io::stdin().read_line(&mut s).unwrap();
    std::io::stdin().read_line(&mut t).unwrap();

    let mut result = 0;

    for i in 0..s.len() {
        if s.as_bytes()[i] != t.as_bytes()[i] {
            result = result + 1;
        }
    }
    println!("{}", result);
}


fn main() {
    let mut input1 = String::new();
    std::io::stdin().read_line(&mut input1).unwrap();
    let mut input2 = String::new();
    std::io::stdin().read_line(&mut input2).unwrap();
    println!("{}", input1.chars().zip(input2.chars()).filter(|(a, b)| a != b).count());
}


use proconio::input;

pub fn calc(s: Vec<char>, t: Vec<char>) -> u16 {

    let len = s.len();
    let mut ans = 0;
    for i in 0 .. len {
        if s[i] != t[i] { ans += 1 };
    }
    ans
}

fn main() {
    input! {
        s: String,
        t: String,
    }
    let s: Vec<char> = s.chars().collect();
    let t: Vec<char> = t.chars().collect();

    let result = calc(s, t);
    println!("{}", result);
}


use proconio::input;

pub fn calc(before: &String, after: &String) -> u16 {
    let s: Vec<char> = before.chars().collect();
    let t: Vec<char> = after.chars().collect();
    let len = s.len();
    let mut ans = 0;
    for i in 0 .. len {
        if s[i] != t[i] { ans += 1 };
    }
    ans
}

fn main() {
    input! {
        before: String,
        after: String,
    }

    let result = calc(before, after);
    println!("{}", result);
}


pub fn calc(before: &String, after: &String) -> u16 {
    let mut count = 0;
    for (s, t) in before.chars().zip(after.chars()) {
        if s != t {
            count += 1;
        }
    }
    count
}

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()
}

fn read_vec<T: std::str::FromStr>() -> Vec<T> {
    read::<String>()
        .split_whitespace()
        .map(|e| e.parse().ok().unwrap())
        .collect()
}

fn main() {
    let v = read_vec::<String>();
    let before = &v[0];
    let w = read_vec::<String>();
    let after = &w[0];
    let result = calc(before, after);
    println!("{}", result)
}


let S: String = readLine()!
let T: String = readLine()!
var res: Int = 0
var idx: String.Index = S.startIndex

for _ in 1...S.count {
    if S[idx] != T[idx] { res += 1 }
    idx = S.index(after: idx)
}
print(res)	// (๑•ૅㅁ•๑)


let S = Array(readLine()!)
let T = Array(readLine()!)

var count = 0

for i in 0..<S.count {
  if S[i] != T[i] {
    count += 1
  }
}
print(count)


let s = readLine()!
let t = readLine()!

print(zip(s, t).filter { $0 != $1 }.count)


//
//  main.swift
//
//  Created by sun-yryr
//  Copyright © 2019 sun-yryr. All rights reserved.
//

import Foundation

prefix operator *
prefix func * <T> (a: [T]) -> (T, T) {return (a[0], a[1])}
prefix func * <T> (a: [T]) -> (T, T, T) {return (a[0], a[1], a[2])}

func readInt(separator s: Character = " ") -> [Int] {return readLine()!.split(separator: s).map({Int($0)!})}
func readDouble(separator s: Character = " ") -> [Double] {return readLine()!.split(separator: s).map({Double($0)!})}
func readElement(separator s: Character = " ") -> [String] {return readLine()!.split(separator: s).map({String($0)})}

extension String {
    func at(_ i: Int) -> Character {
        precondition(0 <= i && i < self.count)
        return self[self.index(self.startIndex, offsetBy: i)]
    }
}

func main() {
    let s = readLine()!
    let t = readLine()!
    var counter = 0
    for (i, j) in zip(s, t) {
        if (i == j) {
            counter += 1
        }
    }
    print(counter)
}
main()


//
//  main.swift
//
//  Created by sun-yryr
//  Copyright © 2019 sun-yryr. All rights reserved.
//

import Foundation

prefix operator *
prefix func * <T> (a: [T]) -> (T, T) {return (a[0], a[1])}
prefix func * <T> (a: [T]) -> (T, T, T) {return (a[0], a[1], a[2])}

func readInt(separator s: Character = " ") -> [Int] {return readLine()!.split(separator: s).map({Int($0)!})}
func readDouble(separator s: Character = " ") -> [Double] {return readLine()!.split(separator: s).map({Double($0)!})}
func readElement(separator s: Character = " ") -> [String] {return readLine()!.split(separator: s).map({String($0)})}

extension String {
    func at(_ i: Int) -> Character {
        precondition(0 <= i && i < self.count)
        return self[self.index(self.startIndex, offsetBy: i)]
    }
}

func main() {
    let s = readLine()!
    let t = readLine()!
    var counter = 0
    for i in 0..<s.count {
        if (s.at(i) == t.at(i)) {
            counter += 1
        }
    }
    print(counter)
}
main()


let S = readLine()!
let T = readLine()!
var times = 0
var s = Array(S)
var t = Array(T)
for i in 0..<s.count{
    if s[i] == t[i]{
        times += 1
    }
}
print(times)


import * as fs from "fs";

function strArr2numArr(strArr: string[]): number[] {
    let numArr: number[] = [];
    strArr.map((item) => {
        numArr.push(+item);
    });
    return numArr;
}

const MOD: number = 1e9 + 7;

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

let s: string = input[0];
let t: string = input[1];

let ans: number = 0;

for (let i = 0; i < s.length; i++) {
    if (s[i] !== t[i]) ans++;
}

console.log(ans);


import * as fs from 'fs';

// main
function main(input: string[]) {
    // param
    var s: string;
    var t: string;
    var ans: number;
    // init
    s = input[0];
    t = input[1];
    // solve
    ans = 0;
    for (var i = 0; i < s.length; i ++) {
        if (s[i] != t[i]) ans ++;
    }
    // answer
    console.log(ans);
}

// graph lib
/*
function GRAPH_enumPattern(cur: number[], pat: number[][]): number[][] {
    var arr = [];
    for (var patx = 0; patx < pat.length; patx++) {
        var pos = [cur[0] + pat[patx][0], cur[1] + pat[patx][1]];
        arr.push(pos);
    }
    return arr;
}
*/

// math lib
/*
function Math_max(arr: number[]): number { return arr.reduce((x, y) => Math.max(x, y)); }
function Math_min(arr: number[]): number { return arr.reduce((x, y) => Math.min(x, y)); }
function Math_gcd(): number {
    var ans = arguments[0];
    var f = (a: number, b: number): number => b ? f(b, a % b) : a
    for (var i = 1; i < arguments.length; i++) {
        ans = f(ans, arguments[i]);
    }
    return ans
};
function Math_gcdArray(values: number[]): number {
    var ans = values[0];
    var f = (a: number, b: number): number => b ? f(b, a % b) : a
    for (var i = 1; i < values.length; i++) {
        ans = f(ans, values[i]);
    }
    return ans
};
function Math_lcm(): number {
    var a = arguments
    var g = (n: number, m: number): number => m ? g(m, n % m) : n
    var l = (n: number, m: number): number => n * m / g(n, m)
    var ans = a[0]
    for (var i = 1; i < a.length; i++) {
        ans = l(ans, a[i])
    }
    return ans
}
function Math_lcmArray(values: number[]): number {
    var a = values
    var g = (n: number, m: number): number => m ? g(m, n % m) : n
    var l = (n: number, m: number): number => n * m / g(n, m)
    var ans = a[0]
    for (var i = 1; i < a.length; i++) {
        ans = l(ans, a[i])
    }
    return ans
}
function Math_primeList(value: number): number[] {
    var ans = [];
    var arr = new Array(value).fill(0);
    for (var i = 2; i < value; i++) {
        if (arr[i] == 0) {
            for (var j = i; j < value; j += i) {
                if (arr[j] == 0) arr[j] = i;
            }
        }
    }
    for (var i = 2; i < value; i++) {
        if (arr[i] == i) ans.push(i);
    }
    return ans;
}
function Math_primeFactor(p: number[], value: number): number[][] {
    var ans: number[][] = [];
    var valmax = value / 2;;
    for (var i = 0; i < p.length; i++) {
        var prime = p[i];
        if (valmax < prime) break;
        var count = 0;
        while (value % prime == 0) {
            value /= prime;
            count++;
        }
        if (count != 0) {
            ans.push([prime, count]);
        }
        if (value == 1) break;
    }
    return ans;
}
*/

// union-find lib
/*
var g_uf_root: number[];
var g_uf_count: number[];
function UF_initRoot(num: number) {
    g_uf_root = new Array(num).fill(-1);
    g_uf_count = new Array(num).fill(1);
}
function UF_getRoot(index: number) {
    if (g_uf_root[index] < 0) {
        return index;
    } else {
        var work0: number = UF_getRoot(g_uf_root[index]);
        g_uf_root[index] = work0;
        return work0
    }
}
function UF_mergeRoot(a: number, b: number) {
    var root0: number = UF_getRoot(a);
    var root1: number = UF_getRoot(b);
    if (root0 == root1) return;
    if (root0 > root1) [root0, root1] = [root1, root0];
    g_uf_count[root0] += g_uf_count[root1];
    g_uf_count[root1] = 0;
    g_uf_root[root1] = root0;
}
*/

// entrypoint
function entrypoint() {
    try {
        // linux
        var input = fs.readFileSync("/dev/stdin", "utf8").trim().split("\n");
        console.debug = function () { };
        main(input);
    }
    catch (ex) {
        // windows
        const lines: string[] = [];
        // @ts-ignore
        const reader = require('readline').createInterface({
            // @ts-ignore
            input: process.stdin,
            // @ts-ignore
            output: process.stdout
        });
        reader.on('line', function (line: string) {
            lines.push(line);
        });
        reader.on('close', function () {
            input = lines;
            main(input);
        });
    }
}
entrypoint();


export class Main {
  static main(input: string): string {
    const tmp: string[] = input.split("\n");
    const [s]: string[] = tmp.shift().split(" ");
    const [t]: string[] = tmp.shift().split(" ");
    let result = 0;
    for (let i = 0, len = s.length; i < len; i++) {
      if (s.charAt(i) != t.charAt(i)) {
        result++;
      }
    }
    return `${result}`;
  }
}
console.log(Main.main(require("fs").readFileSync("/dev/stdin", "utf8")));


import { readFileSync } from 'fs'
import { reverse } from 'dns'
import { start } from 'repl'

let lines: string[] = [];
const reader = require('readline').createInterface({
    input: process.stdin,
    output: process.stdout
});

reader.on('line', function (line: string) {
    lines.push(line);
});
reader.on('close', function () {
    /* let [n, d] = lines[0].split(' ').map( _ => parseInt(_)) */
    let s = lines[0]
    let t = lines[1]
    let ans = 0
    for(let i = 0; i < s.length(); i++) {
        if(s[i] != t[i]) {
            ans++
        }
    }

    console.log(ans)
});


import { readFileSync } from 'fs'
import { reverse } from 'dns'
import { start } from 'repl'

let lines: string[] = [];
const reader = require('readline').createInterface({
    input: process.stdin,
    output: process.stdout
});

reader.on('line', function (line: string) {
    lines.push(line);
});
reader.on('close', function () {
    /* let [n, d] = lines[0].split(' ').map( _ => parseInt(_)) */
    let s = lines[0]
    let t = lines[0]
    let ans = 0
    for(let i = 0; i < s.length(); i++) {
        if(s[i] != t[i]) {
            ans++
        }
    }

    console.log(ans)
});


n = int(input())

for i in range(9,0,-1):
    (div, mod) = divmod(n, i)
    if 0 < div < 10 and mod == 0:
        print('Yes')
        break
else:
    print('No')


# -*- coding: utf-8 -*-

n = int(input())

kuku = []
for i in range(1,10):
    for j in range(1, 10):
        kuku.append(i*j)

if n in kuku:
    print("Yes")
else:
    print("No")


#ABC144: B - 81

N = int(input())

for i in range(1,10):
    if N % i == 0:
        n = N / i
        for j in range(1,10):
            if n / j == 1:
                print('Yes')
                exit()

print('No')


N=int(input())

for i in range(1,10):
	for j in range(1,10):
		if i+j==N:
			print("Yes")
			exit()

print("No")


N = int(input())

for i in range(1, 10):
    if N % i == 0 and N / i <= 9:
        print('Yes')
        break
    else:
        print('No')


N = int(input())

for i in range(1, 9 + 1):
    if i % N == 0 and N / i <= 9:
        print('Yes')
        break
    else:
        print('No')