#include <iostream>
#include <algorithm>
#include <vector>
#include <iomanip>
#include <string.h>
using namespace std;
#define all(x) (x).begin(), (x).end()

int main(){
    double P, Q;
    cin >> P >> Q;
    cout << fixed << setprecision(10) << double(P * Q) / (P * Q * 2 - P * 100 - Q * 100 + 10000) * 100 << endl;
}