#include <bits/stdc++.h>
using namespace std;
const long long M = 1e9 + 7;
const int mxN = 1000;
long long F[mxN + 1][mxN + 1][5];
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int n, k;
  cin >> n >> k;
  F[1][0][4] = 1;
  for (int i = 2; i <= n; ++i) {
    for (int j = 0; j <= min(i, n); ++j) {
      F[i][j][0] =
          ((i - 3 - j) * F[i - 1][j][0] +
           (i - 2 - j) * (F[i - 1][j][1] + F[i - 1][j][2] + F[i - 1][j][4]) +
           (i - 1 - j) * F[i - 1][j][3]) %
          M;
      if (j + 1 <= i - 1)
        F[i][j][0] =
            (F[i][j][0] + (j + 1) * (F[i - 1][j + 1][0] + F[i - 1][j + 1][4]) +
             j * (F[i - 1][j + 1][1] + F[i - 1][j + 1][2]) +
             (j - 1) * F[i - 1][j + 1][3]) %
            M;
      F[i][j][1] = (F[i - 1][j][2] + F[i - 1][j][3]) % M;
      if (j >= 1)
        F[i][j][1] = (F[i][j][1] + F[i - 1][j - 1][0] + F[i - 1][j - 1][1]) % M;
      F[i][j][2] = (F[i - 1][j][1] + F[i - 1][j][3]) % M;
      if (j >= 1)
        F[i][j][2] = (F[i][j][2] + F[i - 1][j - 1][0] + F[i - 1][j - 1][2]) % M;
      if (j >= 2) F[i][j][3] = F[i - 1][j - 2][4];
      F[i][j][4] = (F[i - 1][j][0] + F[i - 1][j][1] + F[i - 1][j][2] +
                    F[i - 1][j][3] + F[i - 1][j][4]) %
                   M;
    }
  }
  cout << (F[n][k][0] + F[n][k][1] + F[n][k][2] + F[n][k][3] + F[n][k][4]) % M;
}
