There are 19 books, divided into 5 parts, if each part has at least one book, and the number of books in each part is different, how many ways are there in total?
有19本书，分成5份，如果每份至少有一本书，且每份的本数都不相同，一共有多少种分法？
<gadget id="calculator">1 + 1 + 2 + 1</gadget>
<output>5</output>

<result>5</result>