#include <stdio.h>
typedef long long int ll;
constexpr int kMod = int(1E9 + 7);
int a[30][30];
ll dp[30][1 << 21];
int main() {
	int n;
	scanf("%d", &n);
	for (int i = 1; i <= n; i++) for (int j = 1; j <= n; j++) scanf("%d", &a[i][j]);
	dp[0][0] = 1;
	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= n; j++) if (a[i][j]) {
			for (int k = 0; k < (1 << n); k++) if ((1 << (j - 1)) & k) dp[i][k] += dp[i - 1][k ^ (1 << (j - 1))];
		}
		for (int j = 0; j < (1 << n); j++) dp[i][j] %= kMod;
	
	}
	printf("%lld\n", dp[n][(1 << n) - 1]);
}

### Prompt

Please create a solution in cpp to the following problem:

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 <stdio.h>
typedef long long int ll;
constexpr int kMod = int(1E9 + 7);
int a[30][30];
ll dp[30][1 << 21];
int main() {
	int n;
	scanf("%d", &n);
	for (int i = 1; i <= n; i++) for (int j = 1; j <= n; j++) scanf("%d", &a[i][j]);
	dp[0][0] = 1;
	for (int i = 1; i <= n; i++) {
		for (int j = 1; j <= n; j++) if (a[i][j]) {
			for (int k = 0; k < (1 << n); k++) if ((1 << (j - 1)) & k) dp[i][k] += dp[i - 1][k ^ (1 << (j - 1))];
		}
		for (int j = 0; j < (1 << n); j++) dp[i][j] %= kMod;
	
	}
	printf("%lld\n", dp[n][(1 << n) - 1]);
}

```