Лаба 15 2009 год

#include <iostream>

int f(int a);

int main()
{
	int m, n, sum = 0;
	std::cin >> m >> n;


	for (int i = m; i <= n; i += 2) {
		sum += f(i);
	}

	std::cout << sum << '\n';

    return 0;
}

int f(int a)
{
	int fact = 1;
	for (int i = 2; i <= a; i++)
		fact *= i;

	return fact;
}