#include <iostream>
#include <iomanip>

using lint = long long;
using ldouble = long double;

void solve() {
    lint n, g, v;
    std::cin >> n >> g >> v;
    std::cout << std::fixed << std::setprecision(15)
              << ldouble(n / 5) * g / v << std::endl;
}

int main() {
    std::cin.tie(nullptr);
    std::ios::sync_with_stdio(false);

    solve();

    return 0;
}