using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;

namespace RegisteredUSers
{
    internal class Program
    {
        public static void Main(string[] args)
        {
            string input = Console.ReadLine();
            Dictionary<string, string> dic = new Dictionary<string, string>();
            Dictionary<string, string> dic2 = new Dictionary<string, string>();
            while (input != "end")
            {
                string[] inputTokens =
                input.Split(new string[] { " -> " }, StringSplitOptions.RemoveEmptyEntries);

                string key = inputTokens[0];
                string value = inputTokens[1];

                if (dic.ContainsKey(key))
                {
                    dic[key] = value;
                }
                else
                {
                    dic.Add(key, value);
                }



                input = Console.ReadLine();
            }

            string defaultValue = Console.ReadLine();


            foreach (var item in dic)
            {
                if (item.Value == "null")
                {
                    dic2.Add(item.Key, defaultValue);
                }
                else
                {
                    dic2.Add(item.Key, item.Value);
                }

            }
            foreach (var item in dic2.Where(x=> x.Value != defaultValue).OrderByDescending(x=> x.Value.Length))
            {
                Console.WriteLine($"{item.Key} <-> {item.Value}");
            }
            foreach (var item in dic2.Where(x=> x.Value == defaultValue))
            {
                Console.WriteLine($"{item.Key} <-> {item.Value}");
            }
        }
    }
}