public static int diagonalDifference(List<List<Integer>> arr) {
    // Write your code here
    int countp=0,counts =0;
        for(int i=0,j=arr.size()-1;i<arr.size()&&j>=0;i++,j--){
            countp = countp + arr.get(i).get(i);
            counts= counts + arr.get(i).get(j);
        }
        if(countp<=counts){
            return counts-countp;
        }else{
            return countp-counts;
        }
    }