There are 45 students in a class, all of whom borrow extracurricular books, among which 39 borrow Chinese extracurricular books, and 32 borrow math extracurricular books. How many people borrow both kinds of extracurricular books?
某班有学生45人，都借课外书，其中借语文课外书的有39人，借数学课外书的有32人．两种课外书都借的有多少人？
<gadget id="calculator">39 + 32</gadget>
<output>71</output>

<gadget id="calculator">71 - 45</gadget>
<output>26</output>

<result>26</result>