Fold and Sum

using System;
using System.Linq;


namespace wew
{
    class MainClass
    {
        public static void Main(string[] args)
        {
            int[] nums = Console.ReadLine()
                                   .Split(' ')
                                   .Select(int.Parse)
                                   .ToArray();

            int k = nums.Length / 4;

            int[] upperLeft = new int[k];
            int[] upperRight = new int[k];

            int[] upper = new int[k * 2];
            int[] lower = new int[k * 2];

            for (int i = 0; i < k; i++)
            {
                upperLeft[i]  = nums[i];
                upperRight[i] = nums[nums.Length - 1 - i];
            }
            Array.Reverse(upperLeft);

            for (int i = 0; i < k; i++)
            {
                upper[i] = upperLeft[i];
                upper[i + k] = upperRight[i];
            }

            for (int i = 0; i < k * 2; i++)
            {
                lower[i] = nums[i + k];
            }

            int[] sum = new int[k * 2];

            for (int i = 0; i < k * 2; i++)
            {
                sum[i] = lower[i] + upper[i];
            }

            Console.WriteLine(string.Join(" ", sum));
        }
    }
}