using System;
using System.Collections.Generic;
using System.Linq;

class Program
{
    static string InputPattern = "Input3";

    static List<string> GetInputList()
    {
        var WillReturn = new List<string>();

        if (InputPattern == "Input1") {
            WillReturn.Add("1");
            WillReturn.Add("1");
            WillReturn.Add("1 3");
        }
        else if (InputPattern == "Input2") {
            WillReturn.Add("1");
            WillReturn.Add("3");
            WillReturn.Add("2 3");
            WillReturn.Add("3 2");
            WillReturn.Add("2 3");
        }
        else {
            string wkStr;
            while ((wkStr = Console.ReadLine()) != null) WillReturn.Add(wkStr);
        }
        return WillReturn;
    }

    static void Main()
    {
        List<string> InputList = GetInputList();
        int MaruCup = int.Parse(InputList[0]);

        foreach (string EachChangeInfo in InputList.Skip(2)) {
            string[] wkArr = EachChangeInfo.Split(' ');
            int FromCup = int.Parse(wkArr[0]);
            int ToCup = int.Parse(wkArr[1]);

            if (FromCup == MaruCup)
                MaruCup = ToCup;
            else if (ToCup == MaruCup)
                MaruCup = FromCup;
        }
        Console.WriteLine(MaruCup);
    }
}