class Numbers:
    MULTIPLIER=3
    def __init__(self,x,y):
        self.x=x
        self.y=y
    def add(self):
        return self.x+self.y
    @classmethod
    def multiply(cls,a):
        return cls.MULTIPLIER*a
    @staticmethod
    def subtract(b,c):
        return b-c
    @property
    def value(self):
        return (self.x,self.y)
    @value.setter
    def value(self,xy_tuple):
        self.x,self.y=xy_tuple
    @value.deleter