A total of 800 books have been transported into the children's library, including 473 picture book story books and educational books, and 495 picture book story books and children's literature books. Do you know how many picture book story books there are?
少儿图书馆共运进图书800册，其中绘本故事类图书和益智类图书共计473册，绘本故事类图书和少儿文学类图书共计495册，你知道绘本故事类图书有多少册吗？
<gadget id="calculator">495 - 800</gadget>
<output>-305</output>

<gadget id="calculator">473 + (-305)</gadget>
<output>168</output>

<result>168</result>