#include <iostream>

unsigned fac(unsigned n)
{
	unsigned i = 1;
	while (n != 0) i *= n--;
	return i;
}

template<unsigned N> struct Fac    { static unsigned const i = Fac<N - 1>::i * N; };
template<>           struct Fac<0> { static unsigned const i = 1; };

int main()
{
	std::cout << fac(10) << std::endl;
	std::cout << Fac<10>::i << std::endl;
}