class TowerOfHanoi {
	class Peg {
		String name;
		int[] disks = new int[10];
		int topDisk=-1; // topDisk indexes the topMost disk.
		
		/* We give each peg a name, and an initial number of 
		 * disks, whose size is decreasing
		 */
		Peg(String name, int numberOfDisks){
			this.name = name;
			while( numberOfDisks > 0 ){
				addOnTop(numberOfDisks);
				numberOfDisks--;
			}
			System.out.println("Peg " + name + " initialized with " + (topDisk+1));
		}
		
		/* Add disk of specified size to this peg 
		 */				
		public void addOnTop(int disk){
			if (topDisk >= 0 && disk >= disks[topDisk])
				throw new IllegalArgumentException("cheater");
			topDisk++;
			disks[topDisk] = disk;
		}
		
		/* remove the top disk from this peg
		 * return the size of the removed disk
		 */
		public int removeTop(){
			int top = disks[topDisk];
			disks[topDisk] = 0;
			topDisk--;
			return top;
		}
		
		/* move the top disk to the target peg
		 */
		public void moveTopTo(Peg targetPeg){
			int disk;
			disk = removeTop();
			targetPeg.addOnTop(disk);
			System.out.println("moved " + disk + " from peg " + this.name + " to " + targetPeg.name);
		}
		
		/* move the topmost N disks to the target peg
		 * the auxiliary (aux) peg is used as helper in this process
		 */
		public void moveN(int N, Peg target, Peg aux){
			if (N > 0){
				moveN(N-1, aux, target);
				moveTopTo(target);
				aux.moveN(N-1, target, this);
			}
		}
	}
	
	private Peg a,b,c;
	
	public TowerOfHanoi(int numberOfDisks){
		a = new Peg("A", numberOfDisks );
		b = new Peg("B", 0);
		c = new Peg("C", 0);
		
		a.moveN(numberOfDisks , c, b);
	}
	
	
	public static void main(String[] args){
		new TowerOfHanoi(3);
	}
}