import java.util.*;

public class TreeDraw {

    public static void treeDraw(int depth,double x,double xLow,double xHi,double y,double dY){
	StdDraw.filledCircle(x,y,0.005);
	if (depth == 0) return;
	double xLeft  = (xLow + x)/2.0;
	double xRight = (x + xHi)/2.0;
	StdDraw.line(x,y,xLeft,y+dY);
	StdDraw.line(x,y,xRight,y+dY);
	treeDraw(depth-1,xLeft,xLow,x,y+dY,dY);
	treeDraw(depth-1,xRight,x,xHi,y+dY,dY);
    }

    public static void main(String[] args){

	String commands = "\nTreeDraw (version 2.7182)";
	System.out.println(commands);
	Scanner sc = new Scanner(System.in);

	System.out.print("> ");
	String command = sc.next();

	while (!command.equals("quit") && !command.equals("q")){

	    if (command.equals("help")) System.out.println(commands);
	
	    if (command.equals("draw") || command.equals("d")){
		StdDraw.clear();
		System.out.print(">> ");
		int n = sc.nextInt();
		treeDraw(n,0.5,0.0,1.0,1.0,-0.1);
	    }

	    System.out.print("> ");
	    command = sc.next();
      }
	System.exit(0);
  }
}