#include <iostream>

using namespace std;

int main(){
    double value, currentValue;
    double discount;
    cin >> value;
    cin >> currentValue;

    discount = ((value - currentValue) / value)*100;

    cout << discount;

    return 0;
}

#include <bits/stdc++.h>

using namespace std;

typedef long long LL;

#define rep(i,n) for(LL i=0;i<(n);i++)

int main()
{
    double a, b;

    cin >> a >> b;

    b = a - b;

    a = b/a;
    a *= 100;

    printf("%.10lf",a);

    return 0;
}