There are 37 people in the school music interest group, 20 of them can play accordion, 16 can play piano, 24 can play electronic organ, 8 can play both accordion and piano, and 10 can play both accordion and piano. There are 8 people, at most how many people don't know how to play these three kinds of pianos.
学校音乐兴趣小组有37人，其中有20人会手风琴，16人会钢琴，24人会电子琴，既会手风琴又会钢琴的8人，既会电子琴又会钢琴的10人，即会手风琴又电子琴的8人，这三种琴都不会的至多有多少人．
<gadget id="calculator">24 - 8</gadget>
<output>16</output>

<gadget id="calculator">20 + 16</gadget>
<output>36</output>

<gadget id="calculator">38 - 36</gadget>
<output>2</output>

<result>2</result>