#include <bits/stdc++.h>
using namespace std;

int main(){
    double p, q, r;
    cin >> p >> q;
    p /= 100.0, q /= 100.0;
    r = p * q + (1 - p) * (1 - q);
    r = p * q / r;
    printf( "%.10f\n" , r*100.0 );
    
    return 0;
}