class Point
  attr_accessor :x,:y
  def initialize(x=0, y=0)
    self.x = x
    self.y = y
  end
  def to_s
    
  end
end


class Circle < Point
  attr_accessor :r
  def initialize(x=0, y=0, r=0)
    self.x = x
    self.y = y
    self.r = r
  end
  def to_s
    
  end
end