#include <stdio.h>

int main () {
  int n = 0;
  int m = 0;
  
  int res = 0;
  
  long long a[16] = {};
  long long fact[16] = {};
  long long x[16][16] = {};
  
  res = scanf("%d", &n);
  res = scanf("%d", &m);
  
  fact[0] = 1LL;
  for (int i = 0; i < n; i++) {
    fact[i+1] = fact[i];
    fact[i+1] *= (long long) (i+1);
  }
  
  x[0][0] = 1LL;
  for (int i = 0; i < n; i++) {
    for (int j = 0; j <= i; j++) {
      x[i+1][j+1] = x[i][j];
      x[i+1][j] -= ((long long)i)*x[i][j];
    }
  }
  
  a[n] = fact[n];
  for (int i = n-1; i > 0; i--) {
    a[i] = (-x[n][i])*fact[i];
    for (int j = 0; j <= i; j++) {
      x[n][j] -= x[i][j]*x[n][i];
    }
  }
  
  if (m > n) {
    printf("0\n");
  } else {
    printf("%lld\n", a[m]);
  }
  
  return 0;
}