using System;

​

public class Program

{

    private const int n = 3;

    private const int m = 4;

​

    public static void Main()

    {

        // The task is to switch first line with the last one

        int[,] matrix = new int[,]{{1,2,3,4},

                                 {4,5,6,7},

                                 {7,8,9,10}};

​

        Console.WriteLine("Before:");

        Console.WriteLine();

​

        DisplayMatrix(matrix);

​

        MoveFirstLine(matrix);

​

        Console.WriteLine("After:");

        Console.WriteLine();

​

        DisplayMatrix(matrix);

    }

​

    private static void MoveFirstLine(int[,] matrix)

    {

        // one of the answers

        for (int i = 0; i < m; i++)

        {

            int rememberValue = matrix[0, i];

            matrix[0, i] = matrix[n - 1, i];

            matrix[n - 1, i] = rememberValue;

        }

    }

​

    private static void DisplayMatrix(int[,] matrix)

    {

        for (int i = 0; i < n; i++)

        {

            for (int j = 0; j < m; j++)

            {

                Console.Write(matrix[i, j]);

                Console.Write(",");

            }

​

            Console.WriteLine();

            Console.WriteLine();

        }

    }

}