using System.Collections.Generic;
using System;

public class Hello
{
    static void Main()
    {
        var n = int.Parse(Console.ReadLine().Trim());
        var c = new HashSet<string>();
        var ok = new HashSet<string>();
        var w = new string[2 * n];
        var p = 0;
        for (int i = 0; i < n; i++)
        {
            string[] line = Console.ReadLine().Trim().Split(' ');
            var a = line[0];
            var b = line[1];
            w[p++] = a;
            w[p++] = b;
            c.Add(a);
            if (c.Add(b))
            {
                ok.Add(b);
                c.Remove(b);
            }
        }
        for (int i = 0; i < 2 * n; i++)
            if (ok.Contains(w[i])) Console.WriteLine(w[i]);
    }
}