The third grade students participated in extracurricular interest groups. There were 29 students in the calligraphy group, and 37 students in the airplane model group. Among them, 15 people participated in both the calligraphy group and the airplane model group. How many people are there in these two groups?
三年级同学参加课外兴趣小组，参加书法小组的同学有29人，参加航模小组的同学有37人，其中有15人既参加书法小组又参加航模小组，这两个小组共有多少人？
<gadget id="calculator">37 - 15</gadget>
<output>22</output>

<gadget id="calculator">29 + 22</gadget>
<output>51</output>

<result>51</result>