Малко Схеми

using System;
using System.Linq;
using System.Collections.Generic;

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

            int proportion = numbers.Length / 4;

            int[] leftProportion = numbers.Take(proportion).Reverse().ToArray();
            int[] rightProportion = numbers.Skip(proportion * 3).Take(proportion).Reverse().ToArray();
            int[] firstRow = leftProportion.Concat(rightProportion).ToArray();
            int[] secondRow = numbers.Skip(proportion).Take(proportion * 2).ToArray();
            int[] result = firstRow.Select((number, index) => (number + secondRow[index])).ToArray();

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