#include <bits/stdc++.h>
using namespace std;
int main(int argc, char* argv[]) {
  int l, p, q;
  scanf("%d", &l);
  scanf("%d%d", &p, &q);
  int sum = p + q;
  int value = p * l;
  printf("%.4f", (float)value / sum);
  return 0;
}
