#include <stdio.h>
#include <algorithm>
#include <vector>
#include <deque>
#include <string>
#include <iostream>
using namespace std;
using ll = long long;

void solve();
int main() {
	solve();
#ifdef DBG
	while (true);
#endif
}


//379
void solve() {
	ll n, g, v;
	scanf("%lld %lld %lld", &n, &g, &v);
	g *= n / 5;
	printf("%.12lf\n", ((double)g) / ((double)v));
}