03.Spyfer

namespace _03.Spyfer
{
    using System;
    using System.Collections.Generic;
    using System.Linq;

    public class Program
    {
        public static void Main()
        {
            List<int> coordinates = Console.ReadLine()
                .Split()
                .Select(int.Parse)
                .ToList();

            for (int i = 0; i < coordinates.Count; i++)
            {
                int currentNumber = coordinates[i];

                if (i != 0 && i != coordinates.Count - 1)
                {
                    if (currentNumber == coordinates[i - 1] + coordinates[i + 1])
                    {
                        coordinates.RemoveAt(i + 1);
                        coordinates.RemoveAt(i - 1);

                        i = 0;
                    }
                }
                else if (i == 0 && currentNumber == coordinates[i + 1])
                {
                    coordinates.RemoveAt(i + 1);
                    i = 0;
                }
                else if (i == coordinates.Count - 1
                    && currentNumber == coordinates[i - 1])
                {
                    coordinates.RemoveAt(i - 1);
                    i = 0;
                }

            }

            Console.WriteLine(string.Join(" ", coordinates));
        }
    }
}