#利用完全动态的__getattr__,链式调用
class chain(object):
	def __init__(self,path=''):
		self._path=path
	def __getattr__(self,path):
		return ('%s/%s'%(self._path,path))
	def __str__(self):
		return self._path
	__repr__=__str__
# your code goes here
# your code goes here
# your code goes here