using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;
using System.Runtime.Intrinsics.Arm;

class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    static string[] SList(long n) => Enumerable.Repeat(0, (int)n).Select(_ => ReadLine()).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var n = NN;
        var s = SList(n);
        var fail = new HashSet<string>();
        foreach (var si in s)
        {
            var t = si.Split();
            fail.Add(t[0]);
        }
        var all = new HashSet<string>();
        var ans = new List<string>();
        foreach (var si in s)
        {
            var t = si.Split();
            if (all.Add(t[1]) && !fail.Contains(t[1])) ans.Add(t[1]);
        }
        WriteLine(string.Join("\n", ans));
    }
}