import javax.swing.JOptionPane;

public class StringHanoi {
    
    public static void main(String[] args) {
        String start = "One";
        String finish = "Two";
        String aux = "Aux";
        String input = JOptionPane.showInputDialog("Enter the number of disks to move");
        while( input != null ) {
            try {
                int n = Integer.parseInt(input);
                JOptionPane.showMessageDialog(null,moveDisks(n,start,finish,aux));
                input = JOptionPane.showInputDialog("Enter the number of disks to move");
            } catch(NumberFormatException e) {
                input = JOptionPane.showInputDialog("Input Error! Enter only digits.");
            } // end try/catch
        } // end while
    } // end main
    
    static String moveDisks(int n, String start, String finish, String aux) {
        String out = "";
        if( n == 0 ) return out;
        out = moveDisks(n-1,start,aux,finish);
        out += "Move disk " + n + " from " + start + " to " + finish + "\n";
        out += moveDisks(n-1,aux,finish,start);
        return out;
    } // end moveDisks
    
} // end StringHanoi