32 people from Class 1 participated in the Chinese and mathematics competitions. There are 18 people participating in the Chinese competition, 20 people participating in the mathematics competition, and how many people participated in both the language and mathematics competitions.
六1班有32人参加了语文和数学竞赛．参加语文竞赛的有18人，参加数学竞赛的有20人，语数竞赛都参加的有多少人．
<gadget id="calculator">18 - 32</gadget>
<output>-14</output>

<gadget id="calculator">20 + (-14)</gadget>
<output>6</output>

<result>6</result>