04. Equal Pairs

using System;

namespace Equal_Pairs
{
    class Program
    {
        static void Main(string[] args)
        {
            int countNum = int.Parse(Console.ReadLine());

            double beforePearSum = 0;
            double maxDiff = 0;
            double pear = 0;
            int i = 0;
            double num1 = 0;
            double num2 = 0;


            for (; i < countNum; i++)
            {
                if (i == 0)
                {
                    num1 = double.Parse(Console.ReadLine());
                    num2 = double.Parse(Console.ReadLine());

                    beforePearSum = num1 + num2;
                }
                else
                {
                    num1 = double.Parse(Console.ReadLine());
                    num2 = double.Parse(Console.ReadLine());

                    pear = num1 + num2;

                    double Diff = Math.Abs(pear - beforePearSum);
                    if (Diff > maxDiff)
                    {
                        maxDiff = Diff;
                    }
                    beforePearSum = pear;
                }
            }


            if (i == 1 && num1 == num2)
            {
                Console.WriteLine($"Yes, value={beforePearSum}");
            }
            else if (maxDiff == 0)
            {
                Console.WriteLine($"Yes, value={pear}");
            }
            else
            {
            Console.WriteLine($"No, maxdiff={maxDiff}");
            }



        }
    }
}