Among the 100 students in a certain school who participated in a competition of language, mathematics and foreign language, 39 participated in the Chinese competition, 49 participated in the mathematics competition, 41 participated in the foreign language competition, and 39 participated in both Chinese and mathematics competitions. Among the 14 people, 13 people participated in both mathematics and foreign language competitions, 9 people participated in both Chinese and foreign language competitions, and 1 person did not participate in these three competitions. How many people participated in all three events?
某校100名学生在一次语、数、外三科竞赛中，参加语文竞赛的有39人，参加数学竞赛的有49人，参加外语竞赛的有41人，既参加语文又参加数学竞赛的有14人，既参加数学又参加外语竞赛的有13人，既参加语文又参加外语竞赛的有9人，有1人这三项竞赛都不参加．则三项都参加的共有多少人？
<gadget id="calculator">100 - 39 - 49 - 41 - 1</gadget>
<output>-30</output>

<gadget id="calculator">9 + 13 + 14 + (-30)</gadget>
<output>6</output>

<result>6</result>