#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
#pragma GCC optimize("inline")
using namespace std;
const int N = 2005, INF = 0x3f3f3f3f;
const long long MOD = 1000000007;
int n, k;
long long f[N][N][2][2], C[N][N], g[N], fac[N] = {1};
void init() {
  for (register int i = 0; i <= n; i++) {
    f[i][0][0][0] = 1;
    for (register int j = 0; j <= n; j++) {
      if (!i && j) continue;
      for (register int a = 0; a < 2; a++)
        for (register int b = 0; b < 2; b++) {
          (f[i + 1][j][b][0] += f[i][j][a][b]) %= MOD;
          if (!a && i) (f[i + 1][j + 1][b][0] += f[i][j][a][b]) %= MOD;
          (f[i + 1][j + 1][b][1] += f[i][j][a][b]) %= MOD;
        }
    }
  }
  for (register int i = 1; i <= n; i++) {
    C[i][0] = C[i][i] = 1;
    for (register int j = 1; j < i; j++)
      C[i][j] = (C[i - 1][j] + C[i - 1][j - 1]) % MOD;
  }
  for (register int i = 1; i <= n; i++) fac[i] = fac[i - 1] * i % MOD;
}
void solve() {
  for (register int i = n; i >= 0; i--) {
    long long Left = (f[n][i][1][0] + f[n][i][0][0]) * fac[n - i] % MOD;
    long long Right = 0;
    for (register int j = n; j > i; j--) Right = (Right + C[j][i] * g[j]) % MOD;
    g[i] = ((Left - Right) % MOD + MOD) % MOD;
  }
}
signed main() {
  scanf("%d%d", &n, &k);
  init();
  solve();
  printf("%lld\n", g[k]);
  return 0;
}
