#include <iostream>
using namespace std;

// n choose k, combination method using factorials

int main()
{
	int n, k, k_Fact, n_Fact, result, k_nFact;

	cout << "Please enter the n and k by space" << endl;
	cin >> n >> k;

	n_Fact = 1;
	for (int i = 1; i <= n; i++) {
		n_Fact *= i;
	}

	k_Fact = 1;
	for (int i = 1; i <= k; i++) {
		k_Fact *= i;
	}
	
	k_nFact = 1;
	for (int i = 1; i <= (n-k); i++) {
		k_nFact *= i;
	}

	result = n_Fact / (k_Fact* k_nFact);

	cout << "The result is " << result << endl;

	return 0;
}