#include <iostream>
using namespace std;
bool isSafeToPlace(int board[][10], int i, int j, int n) {
for (int row = 0; row < i; row++) {
if (board[row][j] == 1) {
return false;
}
}
int x = i, y = j;
//checks for left diagonal
while (x >= 0 and y >= 0) {
if (board[x][y] == 1) {
return false;
}
x--;
y--;
}
x = i, y = j;
//checks for right diagonal
while (x >= 0 and y < n) {
if (board[x][y] == 1) {
return false;
}
x--;
y++;
}
return true;
}
int permute(int board[][10], int i, int n, int cnt) {
//base case
if (i == n) {
return 1;
}
//recursive case
int count = 0;
for (int j = 0; j < n; j++) {
if (isSafeToPlace(board, i, j, n)) {
board[i][j] = 1;
count += permute(board, i + 1, n, cnt);
//backtrack
//means i and j are not in the right position
//assumption is wrong
board[i][j] = 0;
}
}
return count;
}
int main() {
int n;
cin >> n;
int board[10][10] = {0};
cout << permute(board, 0, n, 0) << endl;
}
