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());
            int currentSum = 0;
            int previousSum = 0;
            int diff = 0;
            int maxDiff = 0;

            for (int i = 0; i < N; i++)
            {
                previousSum = currentSum;
                currentSum = 0;
                for (int j = 1; j <= 2;j++)
                {
                    currentSum += int.Parse(Console.ReadLine());
                }

                if (i != 0) // този if няма да се изпълни при първото завъртане на for i
                {
                    diff = Math.Abs(currentSum - previousSum);
                    if (diff != 0 && diff > maxDiff)
                    {
                        maxDiff = diff;
                    }
                }
            }
            if (maxDiff == 0 || N == 1)
            {
                Console.WriteLine("Yes, value= {0}", currentSum);
            }
            else
            {
                Console.WriteLine("No, maxDiff= {0}", maxDiff);
            }
        }
    }
}