import java.util.Scanner;
public class Main {
		static int INF = 2 << 27;
		public static void main(String[] args) {
			Scanner sc = new Scanner(System.in);
			int N = sc.nextInt();
			int K = sc.nextInt();
			int ans = dfs(0,K,new int[N],new boolean[N],false);
			System.out.println(ans);
		}
		static int dfs(int a, int b, int[] c, boolean[] d, boolean e) {
			if(a == 0) {
				c[a] = b;
				d[b-1] = true;
				return dfs(a+1,b,c,d,e);
			}
			if(a == c.length) {
				if(e)
				return 1;
				return 0;
			}
			int ret = 0;
			for(int i = 0; i < c.length; i++) {
				if(d[i]) continue;
				boolean nex = e;
				if(c[a-1] > i+1) {
					if(e) continue;
					nex = true;
				}
				c[a] = i+1;
				d[i] = true;
				ret += dfs(a+1,b,c,d,nex);
				c[a] = 0;
				d[i] = false;
			}
			return ret;
		}

}