#include <bits/stdc++.h>
using namespace std;
const int maxn = 1005, mod = 1e9 + 7;
int n, K;
long long f[maxn][maxn][6];
int main() {
  scanf("%d%d", &n, &K);
  f[3][0][0] = 1;
  f[3][2][1] = 1;
  f[3][0][2] = 1;
  f[3][2][2] = 1;
  f[3][2][3] = 1;
  f[3][2][4] = 1;
  for (int i = 3; i < n; i++) {
    for (int k = 0; k <= i; k++) {
      for (int j = 0; j < 5; j++)
        f[i + 1][k][2] = (f[i][k][j] + f[i + 1][k][2]) % mod;
      if (k < i - 1) {
        if (k)
          f[i + 1][k - 1][0] =
              (k * f[i][k][0] % mod + f[i + 1][k - 1][0]) % mod;
        f[i + 1][k][0] =
            ((i - 2 - k) * f[i][k][0] % mod + f[i + 1][k][0]) % mod;
        f[i + 1][k + 1][3] = (f[i][k][0] + f[i + 1][k + 1][3]) % mod;
        f[i + 1][k + 1][1] = (f[i][k][0] + f[i + 1][k + 1][1]) % mod;
      }
      if (k < i) {
        if (k)
          f[i + 1][k - 1][0] =
              ((k - 1) * f[i][k][1] % mod + f[i + 1][k - 1][0]) % mod;
        f[i + 1][k][0] =
            ((i - 1 - k) * f[i][k][1] % mod + f[i + 1][k][0]) % mod;
        f[i + 1][k][3] = (f[i][k][1] + f[i + 1][k][3]) % mod;
        f[i + 1][k + 1][1] = (f[i][k][1] + f[i + 1][k + 1][1]) % mod;
        if (k)
          f[i + 1][k - 1][0] =
              (k * f[i][k][2] % mod + f[i + 1][k - 1][0]) % mod;
        f[i + 1][k][0] =
            ((i - 1 - k) * f[i][k][2] % mod + f[i + 1][k][0]) % mod;
        f[i + 1][k + 2][4] = (f[i][k][2] + f[i + 1][k + 2][4]) % mod;
        if (k) {
          f[i + 1][k - 1][0] =
              ((k - 1) * f[i][k][3] % mod + f[i + 1][k - 1][0]) % mod;
          f[i + 1][k][0] =
              ((i - k - 1) * f[i][k][3] % mod + f[i + 1][k][0]) % mod;
          f[i + 1][k + 1][3] = (f[i][k][3] + f[i + 1][k + 1][3]) % mod;
          f[i + 1][k][1] = (f[i][k][3] + f[i + 1][k][1]) % mod;
        }
      }
      if (k > 1) {
        f[i + 1][k - 1][0] =
            ((k - 2) * f[i][k][4] % mod + f[i + 1][k - 1][0]) % mod;
        f[i + 1][k][0] = ((i - k) * f[i][k][4] % mod + f[i + 1][k][0]) % mod;
        f[i + 1][k][3] = (f[i][k][4] + f[i + 1][k][3]) % mod;
        f[i + 1][k][1] = (f[i][k][4] + f[i + 1][k][1]) % mod;
      }
    }
  }
  if (n == 1) {
    if (K == 1)
      cout << 0;
    else
      cout << 1;
    return 0;
  } else if (n == 2) {
    if (K == 0)
      cout << 1;
    else if (K == 2)
      cout << 1;
    else
      cout << 0;
    return 0;
  }
  long long ans = 0;
  for (int j = 0; j < 5; j++) ans = (f[n][K][j] + ans) % mod;
  cout << ans;
  return 0;
}
