#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)

int main() {
    int a, b;
    cin >> a >> b;
    printf("%.6lf", (((double)(a - b) / (double)a) * 100));
}
#include <bits/stdc++.h>
#define rep(i,n) for (int i = 0; i < (n); ++i)
using namespace std;
using ll = long long;
using P = pair<int,int>;

int main(){
	double a,b;
	cin >> a>> b;
	cout << fixed << setprecision(15) << (a-b)/a*100 << endl;
	return 0;
}

// cout << fixed << setprecision(15) <<  << endl;
