Each student in Class 41 participates in at least one interest group. There are 32 people in the art group, 36 people in the calligraphy group, and 15 people in both. How many people are there in Class 41?
四1班每个同学至少参加一项兴趣小组，参加美术小组的有32人，参加书法小组的有36人，两项都参加的有15人，四1班有多少人．
<gadget id="calculator">32 + 36</gadget>
<output>68</output>

<gadget id="calculator">68 - 15</gadget>
<output>53</output>

<result>53</result>