using System;
using System.Collections.Generic;
using System.Text;
using System.Linq;
 
class Program
{
    public void Proc()
    {
        Reader.IsDebug = false;
        string[] inpt = Reader.ReadLine().Split(' ');
        
        string name1 = inpt[0];
        string point1 = inpt[1];
        
        inpt = Reader.ReadLine().Split(' ');
        
        string name2 = inpt[0];
        string point2 = inpt[1];
        
        if(point1.Length > point2.Length) {
            point2 = point2.PadLeft(point1.Length, '0');
        } else if(point2.Length > point1.Length) {
            point1 = point1.PadLeft(point2.Length, '0');
        }
        string ans = "-1";
        if(point1.CompareTo(point2) > 0) {
            ans = name1;
        }
        if(point2.CompareTo(point1) > 0) {
            ans = name2;
        }
        Console.WriteLine(ans);

    }


    public class Reader
    {
        public static bool IsDebug = true;
        private static String PlainInput = @"


touritsu 99999999999999999999 P
Peter 99999999999999999998 R


 
";
        private static System.IO.StringReader Sr = null;
        public static string ReadLine()
        {
            if (IsDebug)
            {
                if (Sr == null)
                {
                    Sr = new System.IO.StringReader(PlainInput.Trim());
                }
                return Sr.ReadLine();
            }
            else
            {
                return Console.ReadLine();
            }
        }
        public static int[] GetInt(char delimiter = ' ', bool trim = false)
        {
            string inptStr = ReadLine();
            if (trim)
            {
                inptStr = inptStr.Trim();
            }
            string[] inpt = inptStr.Split(delimiter);
            int[] ret = new int[inpt.Length];
            for (int i = 0; i < inpt.Length; i++)
            {
                ret[i] = int.Parse(inpt[i]);
            }
            return ret;
        }
    }
    static void Main()
    {
        Program prg = new Program();
        prg.Proc();
    }
}