#include "bits/stdc++.h"

using namespace std;

void solve()
{
	double p, q;
	cin >> p >> q;
	cout << fixed << setprecision(9) << (p * q) / (p * q + (100 - p) * (100 - q)) * 100 << endl;
}

int main(void)
{
	solve();
	//cout << "yui(*-v・)yui" << endl;
	return 0;
}