using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace _09.Simple_text_editor
{
    class Program
    {
        static void Main(string[] args)
        {
            int n = int.Parse(Console.ReadLine());

            Stack<char> stack = new Stack<char>();
            Stack<int> undo = new Stack<int>();
            Stack<char> undoAction = new Stack<char>();

            string action = "";
            for (int i = 0; i < n; i++)
            {
                string[] input = Console.ReadLine().Split(' ').ToArray();
                string command = input[1];
                if (input.Length > 1)
                    action = input[2];

                if (command == "1")
                {
                    foreach (var item in action)
                    {
                        stack.Push(item);
                        undo.Push(int.Parse(command));
                        undoAction.Push(item);
                    }
                }
                else if (command == "2")
                    for (int j = 0; j < int.Parse(action); j++)
                        {
                            undoAction.Push(stack.pop);
                            undo.Push(int.Parse(command));
                        }
                else if (command == "3")
                    Console.WriteLine(stack.ElementAt(int.Parse(action)));
                else if (command == "4")
                {
                    if (undo.Pop() == 2)
                        stack.Push(undoAction.Pop());
                    else if (undo.Pop() == 1)
                        stack.Pop();
                }
            }
        }
    }
}