#include <bits/stdc++.h>
using namespace std;
inline int Get_Int() {
  int Num = 0, Flag = 1;
  char ch;
  do {
    ch = getchar();
    if (ch == '-') Flag = -Flag;
  } while (ch < '0' || ch > '9');
  do {
    Num = Num * 10 + ch - '0';
    ch = getchar();
  } while (ch >= '0' && ch <= '9');
  return Num * Flag;
}
int N, M;
long long C[1005][1005], Factorial[1005], DP[1005][1005][4], Ans[1005];
inline void Prepare() {
  for (int i = 0; i <= N; ++i) {
    C[i][0] = C[i][i] = 1;
    for (int j = 1; j < i; ++j)
      C[i][j] = (C[i - 1][j] + C[i - 1][j - 1]) % 1000000007;
  }
  Factorial[0] = 1;
  for (int i = 1; i <= N; ++i) Factorial[i] = Factorial[i - 1] * i % 1000000007;
}
int main() {
  cin >> N >> M;
  Prepare();
  DP[0][0][2] = 1;
  for (int i = 1; i <= N; ++i)
    for (int j = 0; j < i; ++j)
      for (int k = 0; k < 4; ++k) {
        long long Now = DP[i - 1][j][k];
        if (k & 1)
          DP[i][j + 1][k / 2 + 2] =
              (DP[i][j + 1][k / 2 + 2] + Now) % 1000000007;
        if (i < N)
          DP[i][j + 1][k / 2] = (DP[i][j + 1][k / 2] + Now) % 1000000007;
        DP[i][j][k / 2 + 2] = (DP[i][j][k / 2 + 2] + Now) % 1000000007;
      }
  for (int i = 0; i <= N; ++i) {
    for (int j = 0; j < 4; ++j) Ans[i] = (Ans[i] + DP[N][i][j]) % 1000000007;
    Ans[i] = Ans[i] * Factorial[N - i] % 1000000007;
  }
  for (int i = N; i >= 0; --i)
    for (int j = i + 1; j <= N; ++j)
      Ans[i] = (Ans[i] + -Ans[j] * C[j][i]) % 1000000007;
  Ans[M] = (Ans[M] + 1000000007) % 1000000007;
  cout << Ans[M] << endl;
  return 0;
}
