#include <iostream>

//include
//------------------------------------------
#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <stack>
#include <queue>
#include <bitset>
#include <tuple>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <ctime>
#include <climits>

using namespace std;

//conversion
//------------------------------------------
inline int toInt(string s)
{
    int v;
    istringstream sin(s);
    sin >> v;
    return v;
}
template <class T>
inline string toString(T x)
{
    ostringstream sout;
    sout << x;
    return sout.str();
}

//math
//-------------------------------------------
template <class T>
inline T sqr(T x) { return x * x; }

//typedef
//------------------------------------------
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<long long> VL;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef long long LL;

//container util
//------------------------------------------
#define ALL(a) (a).begin(), (a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define PB push_back
#define MP make_pair
#define SZ(a) int((a).size())
#define EACH(i, c) for (auto i = (c).begin(); i != (c).end(); ++i)
#define EXIST(s, e) ((s).find(e) != (s).end())
#define SORT(c) sort((c).begin(), (c).end())

//repetition
//------------------------------------------
#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define REP(i, n) FOR(i, 0, n)

//constant
//--------------------------------------------
const double EPS = 1e-10;
const double PI = acos(-1.0);
const long long INFL = __LONG_LONG_MAX__ / 10;
const int INFI = __INT_MAX__ / 10;

//clear memory
#define CLR(a) memset((a), 0, sizeof(a))

uint64_t popcnt(uint64_t n)
{
    uint64_t c = 0;
    c = (n & 0x5555555555555555) + ((n >> 1) & 0x5555555555555555);
    c = (c & 0x3333333333333333) + ((c >> 2) & 0x3333333333333333);
    c = (c & 0x0f0f0f0f0f0f0f0f) + ((c >> 4) & 0x0f0f0f0f0f0f0f0f);
    c = (c & 0x00ff00ff00ff00ff) + ((c >> 8) & 0x00ff00ff00ff00ff);
    c = (c & 0x0000ffff0000ffff) + ((c >> 16) & 0x0000ffff0000ffff);
    c = (c & 0x00000000ffffffff) + ((c >> 32) & 0x00000000ffffffff);
    return (c);
}

//debug
// #define dump(x) cerr << #x << " = " << (x) << endl;
// #define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" \
//                       << " " << __FILE__ << endl;

const int LimitN = 21;
int A[LimitN][LimitN];

int N;
const int mod = 1e9 + 7;

LL dp[LimitN + 1][1 << LimitN];

int main()
{
    ios::sync_with_stdio(false);

    cin >> N;
    REP(i, N)
    {
        REP(j, N)
        {
            int a;
            cin >> A[i][j];
        }
    }

    dp[0][0] = 1;

    FOR(i, 0, N)
    {
        FOR(msk, 0, 1 << N)
        if (i == popcnt(msk))
        {
            FOR(j, 0, N)
            if (!(msk & (1 << j)) && A[i][j] == 1)
            {
                dp[i + 1][msk | (1 << j)] += dp[i][msk];
                dp[i + 1][msk | (1 << j)] %= mod;
            }
        }
    }

    cout << dp[N][(1 << N) - 1] << endl;
}

Measured memory_bytes: 309504