#include <iostream>
#include <string>
#include <vector>
#include <set>
#include <cmath>
#include <algorithm>
#include <iomanip>

using namespace std;

int main(void)
{
    double N, G, V;
    cin >> N >> G >> V;

    cout << fixed << setprecision(14) << (int)((N / 5.0)) * G / V << endl;

    return 0;
}