using System;
using System.Linq;

namespace _06.EqualSum
{
    class Program
    {
        static void Main(string[] args)
        {
            int[] arr = Console.ReadLine().Split().Select(int.Parse).ToArray();
            int[] arr2 = arr;
            int GivenNumber = GetInt();


            int[] Pairs1 = new int[arr.Length];
            int[] Pairs2 = new int[arr.Length];
            int PairsCounter = 0;
            for (int i = 0; i < arr.Length; i++)
            {
                for (int x = 0; x < arr2.Length; x++)
                {
                    if (x!=i)
                    {
                        if (arr[i] + arr[x] == GivenNumber)
                        {

                            if (!(Pairs1.Contains(arr[i]) && Pairs2.Contains(arr[x])))
                            {
                                Pairs1[i] = arr[i];
                                Pairs2[i] = arr[x];

                                PairsCounter++;
                            }

                        }
                    }

                }
            }
            //-----------------------------------------------------------------------
            //-----------------------------------------------------------------------
            // PRINT
            //-----------------------------------------------------------------------
            for (int i = 0; i <= PairsCounter; i++)
            {

                            Console.WriteLine($"{Pairs1[i]} {Pairs2[i]}");




            }
            //-----------------------------------------------------------------------
            //-----------------------------------------------------------------------

        }
        static int GetInt() { return int.Parse(Console.ReadLine()); }
    }
}