#include <bits/stdc++.h>
using namespace std;
int main() {
  long long int n, ll, rr, a, b;
  cin >> n >> a >> b;
  ll = 0, rr = n;
  while (ll < rr) {
    ll += a;
    rr -= b;
  }
  ll *= 1000000;
  rr *= 1000000;
  while (rr < ll) {
    ll -= a;
    rr += b;
  }
  double xx = double(ll);
  cout << xx / 1000000 << endl;
  return 0;
}
