using System;
using System.Linq;
using System.Text.RegularExpressions;

namespace No342_2{
    public class Program{
        public static void Main(string[] args){
            const char constChar = 'ｗ';
            var strList = Regex.Matches(Console.ReadLine(), $"[^{constChar}]+{constChar}+").Cast<Match>().Select(m => m.Value).ToList();

            if(strList.Count == 0){
                Console.WriteLine();
            }else{
                Func<string, int> charCount = s => s.Count(c => c == constChar);
                var max = strList.Max(charCount);
                strList.Where(s => charCount(s) == max).ToList().ForEach(s => Console.WriteLine(s.Replace($"{constChar}", "")));
            }
        }
    }
}