bool check(int board[8][8], int row, int j, int n) {
    for (int i = 0; i < n; i++) {
        if (board[row][i] == 1) {
            return false;
        }
    }
    for (int i = 0; i < n; i++) {
        if ((board[i][j]) == 1) {
            return false;
        }
    }
    for (int i = 1; i >= 0; i++) {
        if (j - i < 0) {
            break;
        }
            if (board[row - i][j - i] == 1) {
                return false;
            }
    }
    for (int i = 1; i >= 0; i++) {
        if (j - i < 0) {
            break;
        }
        if (board[row + i][j - i] == 1) {
            return false;
        }
    }
    return true;
}

int put(int board[8][8], int column, int count, int n) {
    if (column == n) {
        count++;
    }
    else {
        for (int i = 0; i < n; i++) {
            board[i][column] = 1;
            if (check(board, i, column, n)) {
                put(board, column + 1, count, n);
            }
        }
    }
    return count;
}

int task16() { //Ферзи
    int n, count = 0;
    cin >> n;
    int board[8][8];
    cout << put(board, 0, count, n);
    return 0;
}