def get_number_rows(ai_settings, defender_width):
    """Determine the number of rows of the defense."""
    #random_rows = randint(3,6)
    #available_space_x = (ai_settings.screen_width -
            #(random_rows * defender_width))
    number_rows = 4 #int(available_space_x / (3 * defender_width))
    return number_rows