There are 4 books on the podium, Chinese, Mathematics, English, and Art, and the art book is not placed on the top. How many ways are there in total?
讲台上有4本书，语文、数学、英语、美术，其中美术书不放在最上面，这样的方法一共有多少种？
<gadget id="calculator">3 * 3 * 2 * 1</gadget>
<output>18</output>

<result>18</result>