using System;
using System.Linq;
using System.Collections.Generic;
public class Program
{
	public static void Main()
	{
		List<string> names = Console.ReadLine().Split(',').ToList();
		while(true)
		{
			string command = Console.ReadLine();
			if(command == "END")
			{
				break;
			}
			else if(command == "Add visitor")
			{
				string newName = Console.ReadLine();
				names.Add(newName);
			}
			else if(command == "Remove last visitor")
			{
				names.RemoveAt(names.Count - 1);
			}
			else if(command == "Remove first visitor")
			{
				names.RemoveAt(0);
			}

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