EqualPairs

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

namespace EqualPairs
{
    class Program
    {
        static void Main(string[] args)
        {
            int n = int.Parse(Console.ReadLine());
            var zeroSum = 0;
            var maxDifference = 0;
            bool allPairAreEqual=true;
            for (int i = 0; i < n; i++)
            {
                int firstNumber = int.Parse(Console.ReadLine());
                int secondNumber = int.Parse(Console.ReadLine());

                var pair = firstNumber + secondNumber;

                if (pair != zeroSum && i != 0)
                {
                    allPairAreEqual = false;
                    int difference = Math.Abs(pair - zeroSum);
                    if (difference > maxDifference)
                        maxDifference = difference;  //както е задачата с MaxNumber
                }
                zeroSum = pair; //край на цикъла
            }
                if (allPairAreEqual)
                {
                    Console.WriteLine("Yes, value={0}",zeroSum);
                }
                else
                {
                    Console.WriteLine("No, maxdiff={0}",maxDifference);
                }
            }
    }
}