#include <stdio.h>

int N, K;

int flag[21];

void dfs(int depth, int cnt,int pre);

typedef long long ll;

ll ans;

int main() {

	scanf("%d %d", &N, &K);

	flag[K] = 1;

	dfs(1, 0, K);

	printf("%lld\n", ans);

	return 0;
}
void dfs(int depth, int cnt,int pre) {
	if (cnt >= 2) { return; }

	if (depth == N) {
		if (cnt == 1) { ans++; }
		return;
	}

	int i;

	for (i = 1; i <= N; i++) {
		if (flag[i] == 0 ) {
			if (pre < i) {
				flag[i] = 1;
				dfs(depth+1,cnt,i);
				flag[i] = 0;
			}
			else if (pre > i && cnt==0) {
				flag[i] = 1;
				dfs(depth+1,1,i);
				flag[i] = 0;
			}
		}
	}

}