using System;

class Program
{
    static void Main()
    {
        int n = int.Parse(Console.ReadLine());
        int m = int.Parse(Console.ReadLine());
        int[] p = new int[m];
        int[] q = new int[m];
        for(int i = 0; i < m; i++)
        {
            string[] s = Console.ReadLine().Split();
            p[i] = int.Parse(s[0]);
            q[i] = int.Parse(s[1]);
        }

        int ans = n;

        for (int i = 0; i < m; i++)
        {
            if (p[i] == ans) ans = q[i];
            else
            {
                if (q[i] == ans) ans = p[i];
            }
        }

        Console.WriteLine(ans);
    }
}