using System.Text;
using System;

public class Hello
{
    static void Main()
    {
        var n = int.Parse(Console.ReadLine().Trim());
        var sb0 = new StringBuilder();
        var sb1 = new StringBuilder();
        for (int i = 0; i < n; i++)
        {
            string[] line = Console.ReadLine().Trim().Split(' ');
            if (line[0] == "0") sb0.Append(line[1]);
            else sb1.Append(line[1]);
        }
        var s1 = sb1.ToString().ToCharArray();
        Array.Reverse(s1);
        Console.Write(new string(s1));
        Console.WriteLine(sb0);
    }
}