#include<iostream>
#include<string>
#include<algorithm>
#include<cctype>
#include<set>
#include<bitset>
#include<math.h>
#include<map>
#include<queue>
#include<iomanip>
using namespace std;
#ifdef _WIN32
#include <Windows.h>
#endif

int main()
{
    long long n, g, v, c, r, t;
    string s;
    cin >> n >> g >> v;
    c = n/5;
    printf("%.12f", c*g*1./v);
}