Java 13 - multiply matric

import java.util.*;

class LabTask13 

{ 

static int i,j,r1,c1,r2,c2,k;

public static void main(String... args) 

{ 

Scanner sc=new Scanner(System.in);

System.out.print("Enter the no.of rows of 1st matrix: ");

r1=sc.nextInt();

System.out.print("Enter the no.of columns of 1st matrix: ");

c1=sc.nextInt();

System.out.print("Enter the no.of rows of 2nd matrix: ");

r2=sc.nextInt();

System.out.print("Enter the no.of columns of 2nd matrix: ");

c2=sc.nextInt();

if(c1!=r1) 

{ 

System.out.println("matrix multiplication is not possible");

return ;

} 

int mul[][]=new int[r1][c2];
  System.out.println("Enter first matrix elements:");

int a[][]=new int[r1][c1];

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

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

a[i][j]=sc.nextInt();

} 

} 

System.out.println("Enter second matrix elements:");

int b[][]=new int[r2][c2];

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

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

b[i][j]=sc.nextInt();

} 

} 

System.out.println("Resultant matrix is:");

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

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

mul[i][j]=0;

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

mul[i][j]=a[i][k]*b[k][j];

} 

System.out.print(mul[i][j]+" ");

} 

System.out.println(); }}}