using System;  

public class Exercise21  

{  

    public static void Main()

{

        int i,j,k,r1,c1,r2,c2,sum=0;

        int[,] arr1 = new int[50,50];

        int[,] brr1 = new int[50,50];

        int[,] crr1 = new int[50,50];

       Console.Write("\n\nMultiplication of two Matrices\n");

       Console.Write("----------------------------------\n");  

​

  Console.Write("\nInput the number of rows and columns of the first matrix :\n");     

  Console.Write("Rows : ");

  r1 = Convert.ToInt32(Console.ReadLine());

  Console.Write("Columns : ");  

  c1 = Convert.ToInt32(Console.ReadLine());

​

  Console.Write("\nInput the number of rows of the second matrix :\n");  

  Console.Write("Rows : ");

  r2 = Convert.ToInt32(Console.ReadLine());

  Console.Write("Columns : ");   

  c2 = Convert.ToInt32(Console.ReadLine());  

  if(c1!=r2){

      Console.Write("Mutiplication of Matrix is not possible.");

      Console.Write("\nColumn of first matrix and row of second matrix must be same.");

  }

  else

      {

       Console.Write("Input elements in the first matrix :\n");

       for(i=0;i<r1;i++)

        {

            for(j=0;j<c1;j++)

            {

               Console.Write("element - [{0}],[{1}] : ",i,j);

               arr1[i,j] = Convert.ToInt32(Console.ReadLine());

            }

        }   

       Console.Write("Input elements in the second matrix :\n");

       for(i=0;i<r2;i++)

        {

            for(j=0;j<c2;j++)

            {

               Console.Write("element - [{0}],[{1}] : ",i,j);

               brr1[i,j] = Convert.ToInt32(Console.ReadLine());

            }

        }    

     Console.Write("\nThe First matrix is :\n");

        for(i=0;i<r1;i++)

            {

            Console.Write("\n");

            for(j=0;j<c1;j++)

            Console.Write("{0}\t",arr1[i,j]);

            }

    Console.Write("\nThe Second matrix is :\n");

        for(i=0;i<r2;i++)

            {

            Console.Write("\n");

            for(j=0;j<c2;j++)

            Console.Write("{0}\t",brr1[i,j]);

            }

//multiplication of matrix

      for(i=0;i<r1;i++)

          for(j=0;j<c2;j++)

           crr1[i,j]=0;

             for(i=0;i<r1;i++)    //row of first matrix

                 { 

                   for(j=0;j<c2;j++)    //column of second matrix

                     {  

                       sum=0;

                         for(k=0;k<c1;k++)

                           sum=sum+arr1[i,k]*brr1[k,j];

                           crr1[i,j]=sum;

                     }

                 }

  Console.Write("\nThe multiplication of two matrix is : \n");

  for(i=0;i<r1;i++)

     {

        Console.Write("\n");

        for(j=0;j<c2;j++)

         {

           Console.Write("{0}\t",crr1[i,j]);

         }

     }

  }

Console.Write("\n\n");

  }