#include<bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i =0; i <(n); i++)
using ll = long long;
int main(){
    int a,b;
    cin >> a >> b;
    cout << (double)(a-b)/a*100;
}
#include<bits/stdc++.h>
using namespace std;

int main() {
     double a , b; cin>>a>>b;
     scanf("%lf%lf" , &a,&b);
     double ans = (a - b)/a;
     ans = (ans  * 100.0);
     printf("%.7f" , ans);
}