#include <bits/stdc++.h>
using namespace std;
int main() {
  int L;
  int s1, s2;
  cin >> L >> s1 >> s2;
  double L2, s12, s22;
  L2 = L;
  s12 = s1;
  s22 = s2;
  printf("%f\n", (s12 / (s12 + s22)) * L2);
  return 0;
}
