A book has 150 pages, each page has 24 lines, and each line has 20 characters. What is the maximum number of characters in this book?
一本书有150页，每页排24行，每行排20个字，这本书最多有多少个字？
<gadget id="calculator">20 * 24 * 150</gadget>
<output>72_000</output>

<result>72_000</result>