#include <iostream>
#include <algorithm>
#include <cmath>
#include <vector>
#include <complex>
#include <queue>
#include <deque>
#include <set>
#include <map>
#include <unordered_set>
#include <unordered_map>
#include <iomanip>
#include <assert.h>
#include <array>
#include <cstdio>
#include <cstring>
#include <random>
#include <functional>
#include <numeric>
#include <bitset>
#include <fstream>

using namespace std;

#define REP(i,a,b) for(int i=a;i<(int)b;i++)
#define rep(i,n) REP(i,0,n)
#define all(c) (c).begin(), (c).end()
#define zero(a) memset(a, 0, sizeof a)
#define minus(a) memset(a, -1, sizeof a)
#define watch(a) { cout << #a << " = " << a << endl; }
template<class T1, class T2> inline bool minimize(T1 &a, T2 b) { return b < a && (a = b, 1); }
template<class T1, class T2> inline bool maximize(T1 &a, T2 b) { return a < b && (a = b, 1); }

typedef long long ll;
int const inf = 1<<29;

int main() {

  ll N, G, V; cin >> N >> G >> V;
/*
  double L = 0.0, R = 1e9;
  rep(_, 150) {
    double Ml = (2 * L + R) / 3.0;
    double Mr = (L + 2 * R) / 3.0;
    //N / 5 * G / V
    if(abs(Ml * V * 5 - N * G) <= abs(Mr * V * 5 - N * G)) {
      R = Mr;
    } else {
      L = Ml;
    }
  }
  */

  printf("%.20f\n", (double)(N / 5) * G / V);

//  printf("%.15f\n", (L + R) / 2.0);
  
  return 0;
}