EvenDifferences

namespace Problem2
{
    using System;
    using System.Collections.Generic;

    class EvenDifferences
    {
        static void Main()
        {
            string[] input = Console.ReadLine().Split(' ');
            long[] numbers = new long[input.Length];
            for (int i = 0; i < input.Length; i++)
            {
                numbers[i] = long.Parse(input[i]);
            }



            long sumOfEven = 0;

            for (int i = 1; i < numbers.Length; i++)
            {
                long absDifference = Math.Abs(numbers[i-1]-numbers[i]);
                if (absDifference % 2 == 0)
                {
                    i++;
                    sumOfEven += absDifference;

                }


            }

            Console.WriteLine(sumOfEven);
        }
    }
}