#include <vector>
#include <list>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <algorithm>
#include <sstream>
#include <iostream>
#include <string>
#include <cstdio>
#include <cmath>

using namespace std;

int main() {
	long long N;
	double G, V;
	cin >> N >> G >> V;
	double t = (N / 5);
	printf("%.13f\n", t*G/V);

	return 0;
}