class program
    {
    define halfTurn()
        {
        iterate(2)
            turnleft();
        }

    define sube()
        {
        turnleft();
        move();
        }

    define baja()
        {
        halfTurn();
        move();
        turnleft();
        }

    define subeBeeper()
        {
        pickbeeper();
        sube();
        putbeeper();
        baja();
        }

    define bajaBeeper()
        {
        sube();
        pickbeeper();
        baja();
        putbeeper();
        }

    program()
        {
        while(frontIsClear)
            {
            if(nextToABeeper)
                subeBeeper();
            else
                bajaBeeper();

            move();
            }

        if(nextToABeeper)
            subeBeeper();
        else
            bajaBeeper();

        turnoff();
        }

    }