import a7_1a

class Rectangle(a7_1a.Rectangle):
    """Rectangle that supports + operator.
    """

    def __add__(self, other):
        x = min(self.corner.x, other.corner.x)
        y = min(self.corner.y, other.corner.y)
        mx = max(self.corner.x + self.width,
                other.corner.x + other.width)
        my = max(self.corner.y + self.height,
                other.corner.y + other.height)
        width = mx - x
        height = my - y
        return Rectangle(x, y, width, height)

if __name__ == "__main__":
    r1 = Rectangle(10, 20, 10, 10)
    r2 = Rectangle(20, 50, 15, 20)
    print(r1 + r2)