#include <bits/stdc++.h>
using namespace std;
#define all(x) (x).begin(),(x).end()
#define sz(x) (int)(x).size()
#define FOR(i,a,b) for(int i=(a);i<=(b);++i)
#define FORD(i,a,b) for(int i=(a);i>=(b);--i)
#define pb push_back
#define fi first
#define se second
#define el "\n"
typedef long long ll;
const ll MOD=1e9+7,INF=1e18;
int n,mai[21][21],dp[1<<21];
void solve(){
    cin>>n;
    for (int i=0;i<n;i++)
    {
        for (int j=0;j<n;j++)
        {
            cin>>mai[i][j];
        }
    }
    dp[0]=1;
    int nm=(1<<n);
    for (int m=0;m<nm-1;m++)
    {
        if (dp[m]==0) continue;
        int i=__builtin_popcount(m);
        for (int j=0;j<n;j++)
        {
            if (mai[i][j]==1 and !(m&(1<<j)))
            {
                int nx=m|(1<<j);
                dp[nx]+=dp[m];
            }
        }
    }
    cout<<dp[nm-1]<<el;
}

int main(){
    ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    int t=1;//cin>>t;
    while(t--)solve();
    return 0;
}