import java.io.*;
import java.util.*;

public class Main{

    public static void main(String[] args) throws IOException{
                BufferedReader ir=new BufferedReader(new InputStreamReader(System.in,"UTF-8"));
		String s=ir.readLine();
		ArrayList<String> ans=new ArrayList<>();
		ans.add("");
		int l=0,ma=0;
		while(l<s.length()&&s.charAt(l)=='ｗ') l++;
		for(int i=l;i<s.length();i++){
			if(s.charAt(i)=='ｗ'){
				int st=i;
				while(i<s.length()&&s.charAt(i)=='ｗ') i++;
				if(i-st>ma){
					ma=i-st;
					ans.clear();
					ans.add(s.substring(l,st));
				}
				else if(i-st==ma) ans.add(s.substring(l,st));
				l=i--;
			}
		}
		for(String ss : ans){
			System.out.println(ss);
		}
	}
}