#include <bits/stdc++.h>
using namespace std;
int main() {
  int l, a, b;
  while (~scanf("%d", &l)) {
    scanf("%d%d", &a, &b);
    double t1 = l * 1.0 / (a + b);
    double len1 = t1 * a;
    double t2 = l * 2.0 / (a + b);
    double len2 = t2 * a - len1;
    printf("%.4f\n", len2);
  }
  return 0;
}
