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

const int N=22,M=21e5,zqm=1e9+7;
int f[M],a[N][N];

int main() {
	//freopen("in.txt","r",stdin);
	//freopen("out.txt","w",stdout);
	
	int n; scanf("%d",&n);
	for(int i=0;i<n;++i) {
		for(int j=0;j<n;++j) scanf("%d",&a[i][j]);
	}
	int S=1<<n;
	f[0]=1;
	for(int s=1;s<S;++s) {
		int x=__builtin_popcount(s);
		for(int i=0;i<n;++i) if((s&(1<<i))&&a[x-1][i]) (f[s]+=f[s^(1<<i)])%=zqm;
	}
	printf("%d\n",f[S-1]);
	
	return 0;
}

### Prompt

Please formulate a cpp solution 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 <bits/stdc++.h>
using namespace std;

const int N=22,M=21e5,zqm=1e9+7;
int f[M],a[N][N];

int main() {
	//freopen("in.txt","r",stdin);
	//freopen("out.txt","w",stdout);
	
	int n; scanf("%d",&n);
	for(int i=0;i<n;++i) {
		for(int j=0;j<n;++j) scanf("%d",&a[i][j]);
	}
	int S=1<<n;
	f[0]=1;
	for(int s=1;s<S;++s) {
		int x=__builtin_popcount(s);
		for(int i=0;i<n;++i) if((s&(1<<i))&&a[x-1][i]) (f[s]+=f[s^(1<<i)])%=zqm;
	}
	printf("%d\n",f[S-1]);
	
	return 0;
}

```