using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        List<int[]> list = new List<int[]>();

        //int n = 4;

        list.Add(new int[] { 1, 2, 3, 4 });

        list.Add(new int[] { 5, 6, 6, 7 });

        list.Add(new int[] { 8, 9, 10, 11 });

        var sum = list[0].Select((value, i) => list.Sum(sublist => sublist[i])).ToList()[0];

        //sum.ForEach(Console.WriteLine);

        Console.WriteLine(sum);

        var sumVertical = Enumerable.Range(0, list[0].Length).Select(col => list.Sum(lst => lst[col])).ToList();

        sumVertical.ForEach(Console.WriteLine);

    }

}