text: a = [1,1,2,2,2,3,4,5]
  c=[]
  d=[]
  
  for entry in a:
      if entry not in c:
          c.append(entry)
          d.append(entry)
          print "----"
          print c
          print d
          print "----"
          pass
      if entry in c and entry in d:
          print d
          d.remove(entry)
  print c
  print d
  