fixed

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

namespace ConsoleApplication16
{
    class Program
    {
        static void Main(string[] args)
        {
            int x;
            int sum = 0;


            int y;
            x = int.Parse(Console.ReadLine());
            y = int.Parse(Console.ReadLine());

            for (int i = x; i < y; i++)
            {

                if (sum %2 !=0 )
                  sum = sum + i;
            }

                  Console.WriteLine(sum);


        }
    }
}