#include <cstdio>
#include <cstring>
#include <iostream>
#include <string>
#include <cmath>
#include <bitset>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <deque>
#include <algorithm>
#include <complex>
#include <unordered_map>
#include <unordered_set>
#include <random>
#include <cassert>
using namespace std;
typedef long long int ll;
typedef pair<int, int> P;

int main()
{
	double p, q; cin>>p>>q;
	p/=100; q/=100;
	double ans=p*q/(p*q+(1-p)*(1-q));
	ans*=100;
	printf("%.10lf\n", ans);
	return 0;
}