# coding: utf-8
s=gets.chomp

s = s.sub(/\Aｗ+/, "")
s = s.sub(/[^ｗ]+\Z/, "")

if s.count("ｗ") == s.size then
  puts ""
elsif s.include?("ｗ") == false then
  puts ""
else
  i = 0
  j = 0
  mx = 0
  ss = []
  while i < s.size do
    while j < s.size && s[j] != "ｗ" do
      j += 1
    end

    a = s[i, j-i]
    i = j
    
    while j < s.size && s[j] == "ｗ" do
      j += 1
    end

    n = j - i
    if mx < n then
      mx = n
      ss = [a]
    elsif mx == n then
      ss << a
    end

    i = j
  end

  ss.each do |s|
    puts s
  end
end