import java.io.BufferedInputStream;

import java.util.Scanner;

public class Solution {

void sgu222 () {

Scanner in = new Scanner (new BufferedInputStream (System.in));

int C[][] = new int [11][11];

int n, k, i, j;

for (i = 0; i <= 10; ++i) {

C[i][0] = C[i][i] = 1;

}

for (i = 2; i <= 10; ++i)

for (j = 1; j < i; ++j)

C[i][j] = C[i - 1][j - 1] + C[i - 1][j];

n = in.nextInt(); k = in.nextInt ();

if (k > n) System.out.println ('0');

else {

int ans = 1;

for (i = n; i > n - k; --i) ans *= i;

System.out.println(ans * C[n][k]);

}

}

public static void main(String[] args) {

Solution sguSolver = new Solution ();

sguSolver.sgu222 ();

}

}