class calculator(object):
	def __init__ (self):
	self.current = 0
	def add(self, amount):
	self.current += amount
	return self.current
	def subtract(self, amount):
	self.current -= amount
	return self.current
	def getCurrent(self):
	return self.current
	a = calculator()
	print(a.add(5))
	print(a.subtract(2))