50 students in class 3 and 2 participated in at least one extracurricular activity, 27 of them participated in the basketball team, and 25 participated in the chorus team. How many students participated in both activities?
三2班50个同学至少参加了一项课外活动，其中有27人参加篮球队，有25人参加合唱队，有多少同学两项活动都参加？
<gadget id="calculator">25 - 50</gadget>
<output>-25</output>

<gadget id="calculator">27 + (-25)</gadget>
<output>2</output>

<result>2</result>