#include<bits/stdc++.h>
using namespace std;
#define LL long long

int n,dp[1<<21],a[22][22];
int mod = 1e9+7;

int main() {
	scanf("%d",&n);
	memset(dp,0,sizeof(dp));
	dp[0] = 1;
	for (int i=0; i<n; i++) {
		for (int j=0; j<n; j++) {
			scanf("%d",&a[i][j]);
		}
	}
	for (int i=0; i<(1<<n); i++) {
		int cb = 0;
		for (int j=0; j<n; j++)
			if (i & (1<<j)) cb++;
		for (int j=0; j<n; j++) {
			if (a[cb][j] == 0) continue;
			if (i & (1<<j)) continue;
			dp[i|(1<<j)] += dp[i];
			dp[i|(1<<j)] %= mod;
		}
	}
	printf("%d\n",dp[(1<<n)-1]);
	return 0;
}

### Prompt

Develop a solution in Cpp to the problem described below:

There are N men and N women, both numbered 1, 2, \ldots, N.

For each i, j (1 \leq i, j \leq N), the compatibility of Man i and Woman j is given as an integer a_{i, j}. If a_{i, j} = 1, Man i and Woman j are compatible; if a_{i, j} = 0, they are not.

Taro is trying to make N pairs, each consisting of a man and a woman who are compatible. Here, each man and each woman must belong to exactly one pair.

Find the number of ways in which Taro can make N pairs, modulo 10^9 + 7.

Constraints

* All values in input are integers.
* 1 \leq N \leq 21
* a_{i, j} is 0 or 1.

Input

Input is given from Standard Input in the following format:


N
a_{1, 1} \ldots a_{1, N}
:
a_{N, 1} \ldots a_{N, N}


Output

Print the number of ways in which Taro can make N pairs, modulo 10^9 + 7.

Examples

Input

3
0 1 1
1 0 1
1 1 1


Output

3


Input

4
0 1 0 0
0 0 0 1
1 0 0 0
0 0 1 0


Output

1


Input

1
0


Output

0


Input

21
0 0 0 0 0 0 0 1 1 0 1 1 1 1 0 0 0 1 0 0 1
1 1 1 0 0 1 0 0 0 1 0 0 0 0 1 1 1 0 1 1 0
0 0 1 1 1 1 0 1 1 0 0 1 0 0 1 1 0 0 0 1 1
0 1 1 0 1 1 0 1 0 1 0 0 1 0 0 0 0 0 1 1 0
1 1 0 0 1 0 1 0 0 1 1 1 1 0 0 0 0 0 0 0 0
0 1 1 0 1 1 1 0 1 1 1 0 0 0 1 1 1 1 0 0 1
0 1 0 0 0 1 0 1 0 0 0 1 1 1 0 0 1 1 0 1 0
0 0 0 0 1 1 0 0 1 1 0 0 0 0 0 1 1 1 1 1 1
0 0 1 0 0 1 0 0 1 0 1 1 0 0 1 0 1 0 1 1 1
0 0 0 0 1 1 0 0 1 1 1 0 0 0 0 1 1 0 0 0 1
0 1 1 0 1 1 0 0 1 1 0 0 0 1 1 1 1 0 1 1 0
0 0 1 0 0 1 1 1 1 0 1 1 0 1 1 1 0 0 0 0 1
0 1 1 0 0 1 1 1 1 0 0 0 1 0 1 1 0 1 0 1 1
1 1 1 1 1 0 0 0 0 1 0 0 1 1 0 1 1 1 0 0 1
0 0 0 1 1 0 1 1 1 1 0 0 0 0 0 0 1 1 1 1 1
1 0 1 1 0 1 0 1 0 0 1 0 0 1 1 0 1 0 1 1 0
0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 1 1 0 0 1
0 0 0 1 0 0 1 1 0 1 0 1 0 1 1 0 0 1 1 0 1
0 0 0 0 1 1 1 0 1 0 1 1 1 0 1 1 0 0 1 1 0
1 1 0 1 1 0 0 1 1 0 1 1 0 1 1 1 1 1 0 1 0
1 0 0 1 1 0 1 1 1 1 1 0 1 0 1 1 0 0 0 0 0


Output

102515160

### Response

```cpp
#include<bits/stdc++.h>
using namespace std;
#define LL long long

int n,dp[1<<21],a[22][22];
int mod = 1e9+7;

int main() {
	scanf("%d",&n);
	memset(dp,0,sizeof(dp));
	dp[0] = 1;
	for (int i=0; i<n; i++) {
		for (int j=0; j<n; j++) {
			scanf("%d",&a[i][j]);
		}
	}
	for (int i=0; i<(1<<n); i++) {
		int cb = 0;
		for (int j=0; j<n; j++)
			if (i & (1<<j)) cb++;
		for (int j=0; j<n; j++) {
			if (a[cb][j] == 0) continue;
			if (i & (1<<j)) continue;
			dp[i|(1<<j)] += dp[i];
			dp[i|(1<<j)] %= mod;
		}
	}
	printf("%d\n",dp[(1<<n)-1]);
	return 0;
}

```