floor = [0]         # keeps track of which floor you're on, zero is the default
people = []


def elevator():     # elevator, appends a floor, removes a floor
    result = 0
    raw = raw_input('Up or Down: ')
    if raw == 'up' or raw == 'Up' or raw == 'UP' or raw == 'uP':
        floor.append(1)
    elif raw == 'down' or raw == 'Down' or raw == 'DOWN':
        floor.remove(1)
    return result


def get_off(person):    # adds person to list, based on user input
    people.remove(person)


def get_on(person):     # removes person to list, based on user input
    people.append(person)


def main():
    try:
        print '\n'
        print 'You are on level %s.' % str(len(floor))      # Tells what floor you're on
        print 'Here are your people', people                # Tells who is on your elevator
        print '\n'

        if people:                                          # If there is something in the list, do this
            who_off = raw_input('Who is getting off? ')
            if who_off == '':                               # If no one gets off, ask who gets on
                who_on = raw_input('Who is getting on? ')
                if who_on == '':                            # If no one gets on, ask where to go, UP or DOWN
                    elevator()
                    main()
                print '\n'
            else:                                           # If someone gets off, remove them from elevator
                get_off(who_off)
                who_on = raw_input('Who is getting on? ')   # Ask who gets on
                if who_on == '':                            # If no one gets on, ask where to go, UP or DOWN
                    elevator()
                    main()
                get_on(who_on)                              # If someone gets on, add them, then continue
                elevator()
                main()

        elif not people:                                    # If there is no one on the elevator
            who_on = raw_input('Who is getting on? ')
            if who_on == '':                                # If no one gets on, ask where to go, UP or DOWN
                elevator()
                main()
            print '\n'
            get_on(who_on)                                  # If someone gets on, add them to the elevator
            elevator()
            main()

    finally:
        elevator()
        main()

if __name__ == '__main__':                                  # Ensures that the main() function will be run

    # Gives user knowledge of what happens
    print 'If no one gets on press ENTER.'
    print 'If no one gets off press ENTER.'
    print 'Else, enter in the name of who gets on.'

    main()