#include<fstream>

using namespace std;

ifstream f("copii.in");
ofstream g("copii.out");

int n;
char ch, a[20][20];
int nr_sol, sol[25];
bool v[25][25];

void solutii(int m) {
    int i, j;
    for (int i = 1; i <= m; i++) {
        for (int j = 1; j <= m; j++) {
            v[i][j] = false;
        }
    }
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= n; j++)
            if (a[i][j] == '1')
                v[sol[i]][sol[j]] = true;
    for (int i = 1; i <= m; i++)
        for (int j = 1; j <= m; j++)
            if (i != j && v[i][j] == false)
                return;
    nr_sol++;
}

void backtr(int p, int q) {
    if (p == n + 1) {
        bool is_solution = true;
        for (int i = 1; i <= q; i++) {
            for (int j = 1; j <= q; j++) {
                v[i][j] = false;
            }
        }
        for (int i = 1; i <= n; i++)
            for (int j = 1; j <= n; j++)
                if (a[i][j] == '1')
                    v[sol[i]][sol[j]] = true;
        for (int i = 1; i <= q; i++)
            for (int j = 1; j <= q; j++)
                if (i != j && v[i][j] == false) {
                    is_solution = false;
                    break;
                }
        if (is_solution == true)
            nr_sol++;
        return;
    }
    for (int i = 1; i <= q; i++) {
        sol[p] = i;
        backtr(p + 1, q);
    }
    sol[p] = q + 1;
    backtr(p + 1, q + 1);
}

int main() {
    f >> n;
    f.get();
    for (int i = 1; i <= n; i++)
        f.getline(1 + a[i], 20);

    backtr(1, 0);
    g << nr_sol - 1;
    return 0;
}