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

public class Hello
{
    static void Main()
    {
        var hs = new HashSet<string> { "watermelon", "beachball", "shrinebell" };
        for (int i = 0; i < 2; i++)
        {
            var s = Console.ReadLine().Trim();
            hs.Remove(s);
        }
        Console.WriteLine(hs.ToArray()[0]);
    }
}