using System;

namespace ConsoleCoreApp
{
    public static class Determinant
    {
        public static Int64 FindDeterminant(int[,] matrix)
        {
            int order = matrix.GetLength(0);
            if (order == 1) return matrix[0, 0];
            if (order == 2) return matrix[0, 0] * matrix[1, 1] - matrix[0, 1] * matrix[1, 0];

            Int64 det = 0;
            for (int j = 0; j < order; j++)
                det += matrix[0, j] * FindAlgebraicAddition(0, j, matrix);

            return det;
        }

        public static Int64 FindAlgebraicAddition(int i, int j, int[,] matrix)
        {
            if ((i + j) % 2 == 0) return FindMinor(i, j, matrix);
            else return -FindMinor(i, j, matrix);
        }

        public static Int64 FindMinor(int i, int j, int[,] matrix)
        {
            int orderMainMatrix = matrix.GetLength(0);
            var subMatrix = new int[orderMainMatrix - 1, orderMainMatrix - 1];
            var tempArray = new int[subMatrix.Length];
            int tempIndex = 0;
            for (int k = 0; k < orderMainMatrix; k++)
            {
                for (int m = 0; m < orderMainMatrix; m++)
                {
                    if (i != k && j != m)
                    {
                        tempArray[tempIndex] = matrix[k, m];
                        tempIndex++;
                    }
                }
            }

            tempIndex = 0;
            for (int k = 0; k < orderMainMatrix - 1; k++)
            {
                for (int m = 0; m < orderMainMatrix - 1; m++)
                {
                    subMatrix[k, m] = tempArray[tempIndex];
                    tempIndex++;
                }
            }

            return FindDeterminant(subMatrix);
        }

        public static void Main()
        {
            var matrix = new int[,] {
            {-2, 1, 3, 2},
            {3, 0, -1, 2},
            {-5, 2, 3, 0},
            {4, -1, 2, -3}
            };

            Console.WriteLine(FindDeterminant(matrix));
        }
    }
}