class Bag (object):
    _nBags = 0
    _bags = []

    def __init__ (self, nApples):
        self.nApples = nApples
        Bag._nBags += 1
        Bag._bags.append (self)

    def apples (self):
        return self.nApples

    @staticmethod
    def nBags ():
        return Bag._nBags

    @staticmethod
    def bags ():
        return Bag._bags