Ding Ding and Dongdong each brought some money to the bookstore to buy books. They both took a fancy to a copy of "One Hundred Thousand Whys", but Ding Ding's money was still 17 yuan short, and Dongdong's money was 23 yuan short. The two of them Just enough money to buy this book. What is the price of this book?
丁丁和冬冬各带了一些钱去书店买书，他们都看中了一本《十万个为什么》，可是丁丁带的钱还差17元，冬冬带的钱还差23元，他们两个人带的钱恰好可以买这本书．请问这本书的价格是多少？
<gadget id="calculator">17 + 23</gadget>
<output>40</output>

<result>40</result>