#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using ll = long long;
using ld = long double;

ll N, G, V;
ld ans;

int main() {
  cin >> N >> G >> V;
  ans = ((ld)G * (N / 5)) / V;
  cout << fixed << setprecision(15) << ans << endl;
  return 0;
}