#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <cstdio>
#include <cstring>
#include <cmath>
using namespace std;
using ll = long long;

int main() {
    double p, q;
    cin >> p >> q;
    p /= 100;
    q /= 100;

    double r = p * q / (p * q + (1 - p) * (1 - q));

    printf("%.13f\n", r * 100);

    return 0;
}