#!/usr/bin/python

class pet:

def __init__ (self, n_legs):

self.__n_legs = n_legs

def sleep (self):

print "zzz"

def leg_count (self):

print "i have %d legs" % self.__n_legs

class dog(pet):

def __init__ (self):

pet.__init__(self, 4)

def bark(self):

print "woof"

doug = dog()

doug.leg_count()

doug.bark()

doug.sleep()