#include<bits/stdc++.h>
using namespace std;
#define ll long long
int main(){
    double p,q;
    cin>>p>>q;
    p/=100.0;
    q/=100.0;
    cout<<fixed<<setprecision(10)<<(p*q)/((p*q)+(1.0-p)*(1.0-q))*100.0<<endl;
}