@property
    def width(self):
        return self.__width
    @width.setter
    def width(self,value):
        if not isinstance(value,int):
            raise ValueError('Please enter int!')
        if not value > 0:
            raise ValueError('The width must > 0!')
        self.__width=value
    @property
    def height(self):
        return self.__height
    @height.setter
    def height(self,value):
        if not isinstance(value,int):
            raise ValueError('Please enter int!')
        if not value > 0:
            raise ValueError('The width must > 0!')
        self.__height=value
    @property
    def resolution(self):
        return self.__width * self.__height