using System;
using System.Collections.Generic;
using System.Linq;
class SoftuniParking
{
    static void Main(string[] args)
    {
        int n = int.Parse(Console.ReadLine());
        Dictionary<string, string> inputDict = new Dictionary<string, string>();
        string command;
        string name;
        string plateNum;

        for (int i = 0; i < n; i++)
        {
            string[] input = Console.ReadLine().Split( " ", StringSplitOptions.RemoveEmptyEntries);
            command = input[0];
            name = input[1];
            

            if (command == "register")
            {
                plateNum = input[2];
                if (!inputDict.ContainsKey(name))
                {
                    inputDict.Add(name, plateNum);
                    Console.WriteLine($"{name} registered {plateNum} successfully");
                }
                else
                {
                    Console.WriteLine($"ERROR: already registered with plate number {plateNum}");
                }
            }
            else if(command == "unregister")
            {
                if (!inputDict.ContainsKey(name))
                {
                    Console.WriteLine($"ERROR: user {name} not found");
                }
                else
                {
                    Console.WriteLine($"{name} unregistered successfully");
                    inputDict.Remove(name);
                }
            }
        }
        foreach (var item in inputDict)
        {
            Console.WriteLine($"{item.Key} => {item.Value}");
        }
    }
}