gistfile1.txt

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

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            string[] nums = Console.ReadLine().Split(' ');
            int[] sums = new int[nums.Length / 2];

            int sumsIndex = 0;
            
            for (int i = 0; i < nums.Length - 1; i += 2)
            {
                sums[sumsIndex] = int.Parse(nums[i]) + int.Parse(nums[i + 1]);

                sumsIndex++;
            }
            
            int diff = 0;
            for (int j = 0; j < sums.Length - 1; j++)
            {
             if (Math.Abs(sums[j] - sums[j + 1]) > diff)
                {
                   diff = Math.Abs(sums[j] - sums[j + 1]);
                }
             } 
            // output
            if (diff == 0)
            {
                Console.WriteLine("Yes, value=" + sums[0]);
            }
            else
            {
                Console.WriteLine("No, maxdiff=" + diff);
            } 
            
            }
        }
    }