#include<iostream>
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<algorithm>
#include<vector>
#include<math.h>
#include<iomanip>
#include<stack>
#include<queue>
#include<set>
#include<map>

using namespace std;
using ll = long long;
using ull = unsigned long long;
using ld = long double;
using pint = pair<int , int>;

//const ll mod = 1000000007;
const ll mod = 998244353;
const ld PI = 3.14159265358979;

int main() {
	//ios::sync_with_stdio(false);
	//cin.tie(0);
	cout << fixed << setprecision(15);
	int n , g , v;
	cin >> n >> g >> v;
	n = n / 5;
	ld ans = (ld)n * g / v;
	cout << ans << endl;
	
	return 0;
}