/* Towers of Hanoi
 *
 * Author: Carsten Butz
 * Date: September 2002
 * Modified: February 2003
 *
 * Program to list the moves needed so solve the puzzle 
 * Towers of Hanoi. The three pegs have numbers 1, 2, and 
 * 3, respectively.
 */

import tio.*;

class Hanoi{

  public static void main (String[] args){

    int howMany;

    System.out.print("How many disks do you want to move? ");
    howMany = Console.in.readInt();

    while(howMany != 0)
      {
	move(howMany,1,3);

	System.out.print("How many disks do you want to move? ");
	howMany = Console.in.readInt();
      }

  }

  public static void move(int n, int a, int b){
    int c;

    if(n == 1)
      {
       	System.out.println(a + " -> " + b);
      }
    else
      {
	// clever way of finding the number of the free pole:
	c = 6-(a+b);

	move(n-1,a,c);
	System.out.println(a + " -> " + b);
	move(n-1,c,b);
      }

    return;

  }

}