uva10055

#include <cstdlib>
#include <cstring>
#include <cstdio>
#include <cmath>
#include <algorithm>
#include <vector>
#include <string>
#include <iostream>


using namespace std;


int main(){
    #ifdef LOCAL
    //freopen("in.txt", "r", stdin);
    //freopen("out.txt", "w", stdout);
    #endif
long long a, b;
while(scanf("%lld%lld", &a, &b) != EOF){
        printf("%lld\n", max(a, b) - min(a, b));
}
return 0;
}