class IteratorHelper<T> {
	
	T data;
	Runnable r;
	boolean flag=false;
	public boolean doneflag=false;
	
	public IteratorHelper (Runnable r) { 
		this.r = r;
	}
	
	public void start() {
		//Start the thread which runs the run() method which calls yield to produce the next value of the iterator
		new Thread(r).start();
	}
	
	public synchronized void yield(T v) { 
		
		//Check if the value has been consumed, if not then wait
		if(flag)
		{
		try
		{
			wait();
		}
		catch(Exception ie)
		{
			ie.getMessage();
		}
		}
		//If the value has been consumed by get(), set the next value
		data = v;
		flag = true;
		//Notify the main thread running the get() method
		System.out.println("Yield "+data);
		notify();
	}
	
	public synchronized T get() { 
		
		//Check if the producer has produced a value, if not wait
		try
		{
			if(!flag)
			{
				wait();
			}
		}
		catch(InterruptedException ie)
		{
			ie.getMessage();
		}
		flag=false;
		//Notify the thread yielding values to yield the next value
		notify();
		//Return this value to the next()
		return data;
	}
	
	public void setDone()
	{
		doneflag = true;
	}
	public boolean done(){
		//Yield has completed
		return doneflag;
	}
}