def relete(seq, n=2): 
   """Delete at most n duplicates from the end of seq."""
   if not seq: return seq
   last = seq[-1]
   n -= 1
   for i in xrange(n): 
      try: element = seq[-i -2]
      except IndexError: break
      if element != last: 
         if i: return seq[:-(i + 1) - 1]
         else: return seq
   return seq[:-(n + 1)]