class Light 
{
	private String color;

	public Light() {
		color = "";
	}

	public Light( String color ) {
		this.color = color;
	}

	public String getColor() {
		return color;
	}

	public void setColor( String color ) {
		this.color = color;
	}

	public String toString() {
		return "color = " + color + "\n";
	}
}

class TrafficLight extends Light
{
	public TrafficLight() {
		super("Red");
	}

	public void change()
	{
		if( getColor().equals("Red") )
			setColor("Green");
		else if( getColor().equals("Green") )
			setColor("Yellow");
		else if( getColor().equals("Yellow"))
			setColor("Red");
	}
}

class RailroadCrossingLight extends Light
{
	private boolean flashing;

	public RailroadCrossingLight()
	{	super("Red");
		flashing = false;
	}

	public RailroadCrossingLight( boolean flashing )
	{	super("Red");
		this.flashing = flashing;
	}

	public boolean getFlashing() {
		return flashing;
	} 

	public void setFlashing( boolean flashing ) {
		this.flashing = flashing;
	}

	public String toString() {
		return super.toString() + "flashing = " 
					+ flashing + "\n";
	}

	public void change() {
		flashing = !flashing;
	}
}