#include <bits/stdc++.h>

using namespace std;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  int N, G, V;
  cin >> N >> G >> V;
  long double x = (long double)(N / 5) * G;
  cout << fixed << setprecision(12) << x / V << '\n';
  return 0;
}