#!/usr/bin/python

# http://www.pythonchallenge.com/pc/def/equality.html

import urllib

import re

import string

def get_challenge(subject):

text_src=urllib.urlopen('http://www.pythonchallenge.com/pc/def/%s.html' % subject).read()

text=re.compile('<!--((?:[^-]+|-[^-]|--[^>])*)-->',re.S).findall(text_src)[-1]

return text

text=get_challenge('equality')

print ''.join(re.findall('[^A-Z][A-Z]{3}([a-z])[A-Z]{3}[^A-Z]',text))

# Result:

# linkedlist

# level 4: http://www.pythonchallenge.com/pc/def/linkedlist.php