#!/usr/bin/env python+− import re+− import sys+− +− cn = sys.argv[1]+− +− r1 = '((a?){%s})' % cn+− r2 = 'a{%s}' % cn+− +− m = re.match(r1 + r2 , "a" * int(cn)) +− +− print m.group(0)+−