matrix multiplication in java

Matrix.java

import java.util.*;
class Matrix{
 public static void main(String args[])throws Exception
 {
  Scanner s=new Scanner(System.in);
  int r1,r2,c1,c2;
  
  System.out.println("Enter row and column for matrix1:");
  r1=s.nextInt();
  c1=s.nextInt();
  
  int[][] m1=new int[r1][c1];
  
  System.out.println("Enter the elements of first matrix");
  for(int i=0;i < r1;i++)
  {
   for(int j=0;j < c1;j++)
   {
    m1[i][j]=s.nextInt();
   }
   
  }
  
  System.out.println("Enter row and column for matrix2:");
  r2=s.nextInt();
  c2=s.nextInt();
  
  if(c1!=r2)
  {
    System.out.println("Matrix multiplication is not possible");
  }

  else
  {
   int m2[][] = new int[r2][c2];
   int multiply[][] = new int[r1][c2];
   int sum=0;
 
   System.out.println("Enter the elements of second matrix");
 
   for(int i=0;i < r2;i++)
   {
    for(int j=0;j < c2;j++)
    {
     m2[i][j]=s.nextInt();
    }
   }
   for(int i=0;i < r1;i++)
   {
    for(int j=0;j < c2;j++)
    {   
     for(int k=0;k < r2;k++)
     {
      sum=sum+m1[i][k]*m2[k][j];
     }
     multiply[i][j] = sum;
     sum = 0;
    }
   }
   System.out.println("multiplication of m1*m2 matrices:");
   System.out.println("--------------------------------");
 
   for (int i=0;i < r1;i++)
   {
    for (int j=0;j < c2;j++)
     System.out.print(multiply[i][j]+"\t");
 
    System.out.print("\n");
   }
  }
 }
}

OUTPUT

javac Matrix.java

java Matrix
Enter row and column for matrix1:
3
3
Enter the elements of first matrix
1       2       3
4       5       6
7       8       9
Enter row and column for matrix2:
3 3
Enter the elements of second matrix
9       8       7
6       5       4
3       2       1
multiplication of m1*m2 matrices
--------------------------------
30       24       18
84       69       54
138     114       90