#include <iostream>
#include <iomanip>
using namespace std;

int main() {
	// your code goes here
	long double G,V;
	long long int N;
	std::cin>>N>>G>>V;
	std::cout<<std::showpoint;
	std::cout<<std::fixed<<std::setprecision(12)<<N/5*G/V<<"\n";
	return 0;
}