from math import pi


class Circle:
    def __init__(self, radius=1):
        self.radius = radius

    def __repr__(self):
        return f"Circle({self.radius})"

    @property
    def radius(self):
        return self._radius

    @radius.setter
    def radius(self, radius):
        if radius < 0:
            raise ValueError("Radius cannot be negative")
        self._radius = radius

    @property
    def diameter(self):
        return 2 * self._radius

    @diameter.setter
    def diameter(self, diameter):
        if diameter < 0:
            raise ValueError("Diameter cannot be negative")
        self._radius = diameter / 2

    @property
    def area(self):
        return pi * self._radius ** 2

    @area.setter
    def area(self, area):
        raise AttributeError("Can't set attribute")