2D Arrays solution in C#

This Page Contains the Solution in C# Programming Language for the Day 11 : 2D Arrays, Code Challange of the HackerRank 30 Days of Code.

using System.CodeDom.Compiler;
using System.Collections.Generic;
using System.Collections;
using System.ComponentModel;
using System.Diagnostics.CodeAnalysis;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Runtime.Serialization;
using System.Text.RegularExpressions;
using System.Text;
using System;

class Solution {
    static void Main(string[] args) {
        int[][] arr = new int[6][];

        for (int i = 0; i < 6; i++) {
            arr[i] = Array.ConvertAll(Console.ReadLine().Split(' '), arrTemp => Convert.ToInt32(arrTemp));
        }

        int[] sum = new int[16];
        int hourglass = 0;
        for (int i = 0; i < 4; i++)
        {
            for (int j = 0; j < 4; j++)
            {
                sum[hourglass] = 
                          arr[i][j] + arr[i][j + 1] + arr[i][j + 2]
                        + arr[i + 1][j + 1] 
                        + arr[i + 2][j] + arr[i + 2][j + 1] + arr[i + 2][j + 2];
                hourglass++;
            }
        }
        Array.Sort(sum);
        Console.WriteLine(sum[15]);
    }
}