To find out 2D matrix addition

/*To find out 2D matrix addition*/
/*Save file as: Matrix_Additon.java*/

import java.lang.*;
class Matrix
{
        int l[][],m[][],n[][];
        Matrix()
        {
        l=new int[][] {{1,2,3},{4,5,6},{7,8,9}};
        m=new int[][] {{1,2,3},{4,5,6},{7,8,9}};
        n=new int[3][3];
        }
        void display()
        {
        for(int i=0;i<3;i++)
        {
        for(int j=0;j<3;j++)
        {
  n[i][j]=l[i][j]+m[i][j];        
   System.out.print("  "+n[i][j]);
                
        }
                System.out.println(" ");
        }
        }
}
class Matrix_Additon
{
        public static void main(String arg[])
        {
        Matrix a1=new Matrix();
        a1.display();
 }
}