#include "bits/stdc++.h"
#define in std::cin
#define out std::cout
#define rep(i,N) for(LL i=0;i<N;++i)
typedef long long int LL;

int main()
{
	long double A, B, C;
	in >> A >> B >> C;
	out << std::fixed << std::setprecision(10);
	out << C * (A / B) << std::endl;
}