There are 32 students in class 41, 21 of them participated in the art interest group, 13 participated in the recitation interest group, and 10 participated in both the art interest group and the recitation interest group. How many people in this class did not participate in the interest group ．
四1班共有学生32人，其中有21人参加美术兴趣小组，有13人参加朗诵兴趣小组，有10人既参加美术兴趣小组又参加朗诵兴趣小组，这个班中没有参加兴趣小组的有多少人．
<gadget id="calculator">13 - 10</gadget>
<output>3</output>

<gadget id="calculator">21 + 3</gadget>
<output>24</output>

<gadget id="calculator">32 - 24</gadget>
<output>8</output>

<result>8</result>