#include <bits/stdc++.h>
using namespace std;
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  ;
  double l, s1, s2;
  cin >> l >> s1 >> s2;
  cout << fixed << setprecision(4) << s1 * ((l) / (s1 + s2));
}
