#include <iostream>
#include <cmath>

int main()
{
	float 
                x,
                a,b;
        std::cin >> x;
        std::cout << "a) " << tan(log10(pow(x, 3) / 3) << std::endl;
	
        std::cin >> a >> b;
        std::cout << "в) " << 1 / (a + 1.f/b) << std::endl;
}