Matrix.java

import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Matrix {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int a[][] = new int[n][n];
        for(int a_i=0; a_i < n; a_i++)
        {
            for(int a_j=0; a_j < n; a_j++)
            {
                a[a_i][a_j] = in.nextInt();
            }
        }
        int d1=0;
        int d2=0;

        for(int i=0;i<n;i++)
        {
            for(int j=0;j<n;j++)
            {
                if(i==j)
                    d1=d1+a[i][j];
            }
        }
        //reverse array , check out....
        for(int i=0;i<n;i++)
        {
            d2=d2+ a[i][n-i-1];
        }
        int diff = Math.abs(d1-d2);
        System.out.println(diff);
    }
}