ChangeRows

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace MatrixSoftuni
{
    class Program
    {
        static void Main(string[] args)
        {
            Random rand = new Random();
            int n = int.Parse(Console.ReadLine());
            int m = int.Parse(Console.ReadLine());

            int[,] matrix = new int[n, m];

            for (int i = 0; i < n; i++)
            {
                for (int j = 0; j < m; j++)
                {
                    matrix[i, j] = rand.Next(10);
                }
            }

            for (int i = 0; i < n; i++)
            {
                for (int j = 0; j < m; j++)
                {
                    Console.Write($"{matrix[i, j]} ");
                }
                Console.WriteLine();
            }

            for (int i = 0; i < m; i++)
            {
                // matrix[0, i] <=> matrix[n - 1, i]
                int temp = matrix[0, i];
                matrix[0, i] = matrix[n - 1, i];
                matrix[n - 1, i] = temp;
            }

            Console.WriteLine();
            for (int i = 0; i < n; i++)
            {
                for (int j = 0; j < m; j++)
                {
                    Console.Write($"{matrix[i, j]} ");
                }
                Console.WriteLine();
            }

        }
    }
}