﻿using System;
using System.Linq;

namespace Extract_Middle_1__2_or_3_Elements
{
    class ExtractMiddleElements
    {
        static void Main(string[] args)
        {
            int[] numbers = Console.ReadLine().Split().Select(int.Parse).ToArray();

            if (numbers.Length == 1)
            {
                Console.WriteLine($"{{ {numbers[0]} }}");
            }
            else if (numbers.Length % 2 == 0)
            {
                Console.WriteLine($"{{ {numbers[numbers.Length / 2 - 1]}, {numbers[numbers.Length / 2]} }}");
            }
            else
            {
                Console.WriteLine($"{{ {numbers[numbers.Length / 2 - 1]}, {numbers[numbers.Length / 2]}, {numbers[numbers.Length / 2 + 1]} }}");
            }
        }
    }
}
