There are 48 students in a class, and each of them participates in at least one of the two competitions of running and high jump. It is known that there are 37 students participating in running and 40 students participating in high jump. How many students participate in both competitions? ?
一个班有学生48人，每人至少参加跑步、跳高两项比赛中的一项，已知参加跑步的有37人，参加跳高的有40人，那么这两项比赛都参加的学生有多少人？
<gadget id="calculator">40 - 48</gadget>
<output>-8</output>

<gadget id="calculator">37 + (-8)</gadget>
<output>29</output>

<result>29</result>