#include <iomanip>
#include <iostream>

using namespace std;

int main(int argc, const char* argv[])
{
	size_t N, G, V;
	cin >> N >> G >> V;
	double v = ((N / 5) * (double)G) / (double)V;
	cout << fixed << setprecision(12) << v << endl;
	return 0;
}