class Rectangle:
    def __init__(self, w, h):
        self.w = w
        self.h = h

    def get_width(self):
        return self.w
    
    def get_height(self):
        return self.h
    
    def __call__(self, coef):
        self.w *= coef
        self.h *= coef
        
r = Rectangle(2, 3)
r(4)
print(r.get_width(), r.get_height()) # 8 12