#include <stdio.h>
int main(){
int N, M;
scanf("%d %d", &M, &N);
printf("%d\n", M - N);
return 0;
}
#include <iostream>
using namespace std;
int main(){
int N, M;
cin >> N >> M;
cout << N - M << endl;
return 0;
}
let input = require("fs").readFileSync("/dev/stdin", "utf8");
let lines = input.split("\n");
let N = parseInt(lines.shift());
let M = parseInt(lines.shift());
console.log(N - M);