#include <iostream>

double power(double x, int y)
{
	if (y == 0)
		return 1;
	else if (y > 0)
		return x * power(x, y - 1);
	else
		return (1 / x) * power(x, y + 1);
}

int main() 
{
	std::cout << power(2, 5) << std::endl;
	std::cout << power(2.5, 3) << std::endl;
	std::cout << power(2, -5) << std::endl;
}