There are 800 scientific books and 500 comic books in the library, and the number of scientific books is 2.5 times less than that of story books by 200. How many story books are there in the school library?
图书馆有科技书800本、连环画500本，科技书的本数比故事书的2.5倍少200本．学校图书馆有故事书多少本？
<gadget id="calculator">200 + 800</gadget>
<output>1_000</output>

<gadget id="calculator">1_000 / 2.5</gadget>
<output>400</output>

<result>400</result>