#include using namespace std; const int MAXN = 1e3 + 10, P = 1e9 + 7; int n; long long dp[MAXN][MAXN][2][2]; int main(){ cin >> n; dp[1][0][0][0] = 1, dp[2][0][0][0] = 2; for(int i = 2; i <= n; i++){ for(int j = 0; j <= i; j++){ //N i - 1, i - 3 N i i - 2 (dp[i + 1][j + 1][0][1] += dp[i][j][0][0] * 2) %= P;//Y i + 1 i - 1 ??i - 1?? j + 1 if(j) (dp[i + 1][j - 1][0][0] += j * dp[i][j][0][0]) %= P;//??????x x - 2?? j - 1 (dp[i + 1][j][0][0] += (i + 1 - j - 2) * dp[i][j][0][0]) %= P;//???? //N i - 1, i - 3 Y i i - 2 if(j) (dp[i + 1][j + 1][1][1] += dp[i][j][0][1] * 2) %= P;//Y i + 1 i - 1 ??i - 1?? j + 1 if(j) (dp[i + 1][j - 1][1][0] += (j - 1) * dp[i][j][0][1]) %= P;//???i i - 2?? ????x x - 2?? j - 1 if(j) (dp[i + 1][j - 1][0][0] += dp[i][j][0][1]) %= P;//??i i - 2???N i i - 1 j - 1 if(j) (dp[i + 1][j][1][0] += (i + 1 - (j - 1) - 1 - 2) * dp[i][j][0][1]) %= P;//???? //Y i - 1, i - 3 Y i i - 2 if(j) (dp[i + 1][j + 1][1][1] += dp[i][j][1][1]) %= P;//Y i + 1 i - 1 ??i - 1???i - 3??? j + 1 if(j) (dp[i + 1][j][1][1] += dp[i][j][1][1]) %= P;//Y i + 1 i - 1 N i - 1 i - 3 ??i - 1 i - 3?? j?? if(j) (dp[i + 1][j - 1][1][0] += (j - 2) * dp[i][j][1][1]) %= P;//???i i - 2?i - 1 i - 3?? ????x x - 2?? j - 1 if(j) (dp[i + 1][j - 1][0][0] += dp[i][j][1][1]) %= P;//??i i - 2???N i i - 1 j - 1 if(j) (dp[i + 1][j][1][0] += (i + 1 - (j - 2) - 1 - 2) * dp[i][j][1][1]) %= P;//???? if(j) (dp[i + 1][j + 1][0][1] += dp[i][j][1][0]) %= P;//Y i + 1 i - 1 ??i - 1???i - 3??? j + 1 if(j) (dp[i + 1][j][0][1] += dp[i][j][1][0]) %= P;//Y i + 1 i - 1 N i - 1 i - 3 ??i - 1 i - 3?? j?? if(j) (dp[i + 1][j - 1][0][0] += (j - 1) * dp[i][j][1][0]) %= P;//???i - 1 i - 3?? ????x x - 2?? j - 1 if(j) (dp[i + 1][j][0][0] += (i + 1 - 1 - 1 - (j - 1)) * dp[i][j][1][0]) %= P;//???? } } cout << dp[n][0][0][0]; return 0; }