#!/usr/bin/ruby
# -*- coding: utf-8 -*-
#
# 342.rb: No.342 一番ワロタww - yukicoder
#

### main

s = gets.strip.split('')

pos = 0
n = s.size

pos += 1 while pos < n && s[pos] == "ｗ"

maxlen = 0
maxws = []

while pos < n
  w = ""
  while pos < n && s[pos] != "ｗ"
    w += s[pos]
    pos += 1
  end

  ppos = pos
  while pos < n && s[pos] == "ｗ"
    pos += 1
  end

  len = pos - ppos
  if len > 0
    if maxlen < len
      maxlen = len
      maxws = [w]
    elsif maxlen == len
      maxws << w
    end
  end
end

if maxlen == 0
  puts
else
  maxws.each{|w| puts w}
end