In a class, 20 students participated in the Chinese competition, 18 students participated in the mathematics competition, and 6 students participated in the language and mathematics competition. How many people in this class participated in the language and mathematics competition?
某班有20人参加语文竞赛，18人参加数学竞赛，同时参加语数竞赛的有6人，这个班参加语、数竞赛的有多少人．
<gadget id="calculator">18 - 6</gadget>
<output>12</output>

<gadget id="calculator">20 + 12</gadget>
<output>32</output>

<result>32</result>