#include <stdio.h>
#include <algorithm>

using namespace std;

int A[30], use[30];
int n, k;

int main() {

	freopen("permutari2.in", "r", stdin);
	freopen("permutari2.out", "w", stdout);

    scanf("%d %d", &n, &k);
	for (int i = 1; i <= n; i++)
		A[i] = i;

	int sol = 0;
	do {
		int nr = 0, vmax = 0;
		for (int i = 1; i <= n; i++) {
        	vmax = max(vmax, A[i]);
			if (vmax == i)
				nr++;
		}
			
		if (nr == k)
			sol++;
	} while (next_permutation(A + 1, A + n + 1));

	printf("%d\n", sol);

	return 0;
}