using System;
using System.Collections.Generic;
using System.Linq;
public struct KusaItem{
    public string word;
    public int kusaCnt;
    public KusaItem(string word,int kusaCnt){
        this.word=word;
        this.kusaCnt=kusaCnt;
    }
}
class Kusa{
    static void Main(){
        char[] chars = Console.ReadLine().ToCharArray();
        List<KusaItem> list = new List<KusaItem>();
        int cnt=0;
        string str="";
        for(int i=0;i<chars.Length;i++){
            if(chars[i] != 'ｗ') {
                //Console.WriteLine(chars[i]);
                str+=chars[i];
                cnt=0;
            } else {
                cnt++;
                if((chars.Length-1 > i && chars[i+1] != 'ｗ') || chars.Length-1 <= i){
                    list.Add(new KusaItem(str,cnt));
                    str="";
                }
            }
        }
        int max=0;
        //linqでやりたかった(´・ω・｀) 
        foreach(var item in list)
            if((max < item.kusaCnt) && !String.IsNullOrWhiteSpace(item.word))  max = item.kusaCnt;
        foreach(KusaItem item in list){
            if(item.kusaCnt == max) Console.WriteLine(item.word);
        }
    }
}