#include <bits/stdc++.h>

using namespace std;

int n, total = 0;
bool *col, *diag1, *diag2;

// в этой функции тот самый алгоритм перебора с возвратом
void search(int y){
    if (y == n){
        total++;
        return;
    }
    for (int x=0; x<n; x++){
        if (col[x] || diag1[x+y] || diag2[x-y+n-1]) continue;
        col[x] = diag1[x+y] = diag2[x-y+n-1] = 1;
        search(y+1);
        col[x] = diag1[x+y] = diag2[x-y+n-1] = 0;
    }
}

int main(){
    ios::sync_with_stdio(0);
    cin.tie(0);

    cin >> n;
    col = new bool[n];
    diag1 = new bool[n+(n-1)];
    diag2 = new bool[n+(n-1)];
    search(0);
    cout << total << endl;
    delete[] col;
    delete[] diag1;
    delete[] diag2;

    system("pause");
    return 0;
}