import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

/**
 * Recursion!
 * The towers of Hanoi
 * @author gtowell
 * Created Oct 2019
 */
public class TowersOfHanoi
{
	/** The number of disks in the tower */
	private int count = 0;
	
	/**
	 * Doing all the recursive work.  This fucntion will print out the 
	 * sequence of moved needed to solve a tower of hanoi problem of a given height
	 * @param n the height of the tower
	 * @param start The tower that the disks are on
	 * @param auxiliary The spare tower
	 * @param end The Tower that you want disks to move to
	 */
	public void solve(int n, String start, String auxiliary, String end) 
	{
		if (n == 1)  { // base case of the recursion
			count++;
			System.out.println(count + " " + start + " -> " + end);
			return;
		} 
		else  { // doing the work.
			solve(n - 1, start, end, auxiliary);
			count++;
			System.out.println(count + " " + start + " -> " + end);
			solve(n - 1, auxiliary, start, end);
		}
		return;
	}
	/**
	 * Run the code, getting the number of disks in the twoer from the user.
	 * @param args
	 */
	public static void main(String[] args) 
	{
		TowersOfHanoi towersOfHanoi = new TowersOfHanoi();
		System.out.print("Enter number of discs: ");
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		try {
			int discs = Integer.parseInt(br.readLine());
			towersOfHanoi.solve(discs, "A", "B", "C");
		} catch (IOException ee) {
			System.err.println("Read failure  " + ee);
		}
	}
}