#include <bits/stdc++.h>

using namespace std;

using int64 = 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 - P) * (1 - Q)) * 100.0 << endl;
}