#include <iostream>
#include <vector>
#include <queue>
using namespace std;
typedef long long ll;
typedef vector<vector<int>> matrix;
const int maxn = 1e5 + 10;
const int INF = 2e9;

matrix multiply_by_k(matrix A, int k) {
    matrix res = A;
    int n = (int) A.size(), m = (int) A[0].size();

    for(int i = 0; i < n; i++) {
        for(int j = 0; j < m; j++) {
            res[i][j] *= k;
        }
    }
    return res;
}
matrix add_two_matrices(matrix A, matrix B) {
    int n_a = (int) A.size(), m_a = (int) A[0].size();
    int n_b = (int) B.size(), m_b = (int) B[0].size();

    if(n_a == n_b and m_a == m_b) {
        matrix res = A;
        for(int i = 0; i < n_a; i++) {
            for(int j = 0; j < m_a; j++) {
                res[i][j] = A[i][j] + B[i][j];
            }
        }
        return res;
    }
    cout << "Dimenziite na matricite treba da se isti za da mozhe da gi sobereme istite" << endl;
    return {{0}};
}
matrix subtract_two_matrices(matrix A, matrix B) {
    int n_a = (int) A.size(), m_a = (int) A[0].size();
    int n_b = (int) B.size(), m_b = (int) B[0].size();

    if(n_a != n_b or m_a != m_b) {
        cout << "Dimenziite na matricite treba da se isti za da mozhe da gi sobereme istite" << endl;
        return {{0}};
    }
    matrix res = A;
    for(int i = 0; i < n_a; i++) {
        for(int j = 0; j < m_a; j++) {
            res[i][j] = A[i][j] - B[i][j];
        }
    }
    return res;
}
matrix multiply_two_matrices(matrix A, matrix B) {
    int n_a = (int) A.size(), m_a = (int) A[0].size();
    int n_b = (int) B.size(), m_b = (int) B[0].size();

    if(m_a != n_b) {
        cout << "Matricite ne mozhat da se mnozhat" << endl;
        return {{0}};
    }
    matrix res(n_a, vector<int>(m_b, 0));
    for(int i = 0; i < n_a; i++) {
        for(int j = 0; j < m_b; j++) {
            int c = 0;
            for(int k = 0; k < n_a; k++) {
                c += A[i][k] * B[k][j];
            }
            res[i][j] = c;
        }
    }

    return res;
}
int determinant_of_matrix(matrix A) {
    int sz = (int) A.size();
    if(sz == 2) {
        return (A[0][0] * A[1][1]) - (A[0][1] * A[1][0]);
    }
    int determinant = 0;
    int sign = 1;
    for(int i = 0; i < sz; i++) {
        int n = 0, m = 0;

        matrix tmp(sz - 1, vector<int>(sz - 1, 0));
        for(int j = 0; j < sz; j++) {
            for(int k = 0; k < sz; k++) {
                if(j != 0 and k != i) {
                    tmp[n][m] = A[j][k];
                    if(m < sz - 2) {
                        m++;
                    }
                    else {
                        m = 0;
                        n++;
                    }
                }
            }

        }
        determinant = determinant + sign*(A[0][i]) * determinant_of_matrix(tmp);
        sign *= -1;
    }
    return determinant;
}
void print(matrix A) {
    int n = (int) A.size(), m = (int) A[0].size();
    for(int i = 0; i < n; i++) {
        for(int j = 0; j < m; j++) {
            cout << A[i][j] << " ";
        }
        cout << endl;
    }
    cout << endl;
}
int main() {
    matrix A = {
        {1, 3, 5, 9},
        {1, 3, 1, 7},
        {4, 3, 9, 7},
        {5, 2, 0, 9}

    };
    matrix B = {
        {1, 2, 3},
        {4, 5, 6},

    };

    cout << determinant_of_matrix(A) << endl;
    return 0;
}