import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.NoSuchElementException;
import java.util.Scanner;
 
 
 
public class Main {
	static int cnt;
	static PrintWriter out = new PrintWriter(System.out);
	static FastScanner sc = new FastScanner();
	static Scanner stdIn = new Scanner(System.in);
	public static void main (String[] args) {
		String s = stdIn.nextLine();
		int max = 0;
		ArrayList<String> ans = new ArrayList<String>();
		int id = 0;
		while(s.length() != 0) {
			if(s.substring(0,1).equals("ｗ")) s = s.substring(1);
			else break;
		}
		while(true) {
			if(id >= s.length()) break;
			String str = "";
			for(int i = id; i < s.length(); i++) {
				if(s.substring(i,i+1).equals("ｗ")) {
					id = i;
					break;
				}
				str += s.substring(i, i+1);
				if(i + 1 == s.length()) id = i+1;
			}
			
			for(int i = id; i < s.length(); i++) {
				if(!s.substring(i,i+1).equals("ｗ")) {
					int len = i - 1 - id;
					id = i;
					if(len < max) {
						break;
					}
					else if(len == max) {
						ans.add(str);
					}
					else {
						ans.clear();
						max = len;
						ans.add(str);
					}
					break;
				}
				if(i + 1 == s.length()) {
					int len = i - id;
					id = i + 1;
					if(len < max) {
						break;
					}
					else if(len == max) {
						ans.add(str);
					}
					else {
						ans.clear();
						max = len;
						ans.add(str);
					}
					break;
				}
			}
			
		}
		boolean say = false;
		for(int i = 0; i < ans.size(); i++) {
			if(ans.get(i).length() > 0) {
				say = true;
				System.out.println(ans.get(i));
			}
		}
		if(!say) System.out.println();
		
	}
}
 
 
//------------------------------//
class FastScanner {
    private final InputStream in = System.in;
    private final byte[] buffer = new byte[1024];
    private int ptr = 0;
    private int buflen = 0;
    private boolean hasNextByte() {
        if (ptr < buflen) {
            return true;
        }else{
            ptr = 0;
            try {
                buflen = in.read(buffer);
            } catch (IOException e) {
                e.printStackTrace();
            }
            if (buflen <= 0) {
                return false;
            }
        }
        return true;
    }
    private int readByte() { if (hasNextByte()) return buffer[ptr++]; else return -1;}
    private static boolean isPrintableChar(int c) { return 33 <= c && c <= 126;}
    private void skipUnprintable() { while(hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++;}
    public boolean hasNext() { skipUnprintable(); return hasNextByte();}
    public String next() {
        if (!hasNext()) throw new NoSuchElementException();
        StringBuilder sb = new StringBuilder();
        int b = readByte();
        while(isPrintableChar(b)) {
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }
    public long nextLong() {
        if (!hasNext()) throw new NoSuchElementException();
        long n = 0;
        boolean minus = false;
        int b = readByte();
        if (b == '-') {
            minus = true;
            b = readByte();
        }
        if (b < '0' || '9' < b) {
            throw new NumberFormatException();
        }
        while(true){
            if ('0' <= b && b <= '9') {
                n *= 10;
                n += b - '0';
            }else if(b == -1 || !isPrintableChar(b)){
                return minus ? -n : n;
            }else{
                throw new NumberFormatException();
            }
            b = readByte();
        }
    }
    
    public int nextInt() {
         if (!hasNext()) throw new NoSuchElementException();
         int n = 0;
         boolean minus = false;
         int b = readByte();
         if (b == '-') {
             minus = true;
             b = readByte();
         }
         if (b < '0' || '9' < b) {
             throw new NumberFormatException();
         }
         while(true){
             if ('0' <= b && b <= '9') {
                 n *= 10;
                 n += b - '0';
             }else if(b == -1 || !isPrintableChar(b)){
                 return minus ? -n : n;
             }else{
                 throw new NumberFormatException();
             }
             b = readByte();
         }
    }
    
    public double nextDouble() {
        return Double.parseDouble(next());
    }
    
 
}