In a class of 50 students, 3 extracurricular activity groups were organized, including 25 people in the sports group, 25 people in the music group, and 22 people in the art group; There are 10 students in the two groups of music and art, 9 people in the two groups of art and sports at the same time, and 5 people in both groups. How many people in this class do not participate in these three groups?
在50人的班级中，组织了3个课外活动小组，其中参加体育组的25人，参加音乐组的25人，参加美术组的22人；同时参加音乐、体育两组的11人，同时参加音乐、美术两组的10人，同时参加美术、体育两组的9人，三组都参加的5人，试问在这个班级中这3个小组都未参加的有多少人．
<gadget id="calculator">25 + 25 + 22</gadget>
<output>72</output>

<gadget id="calculator">11 + 10 + 9</gadget>
<output>30</output>

<gadget id="calculator">72 - 30</gadget>
<output>42</output>

<gadget id="calculator">42 + 5</gadget>
<output>47</output>

<gadget id="calculator">50 - 47</gadget>
<output>3</output>

<result>3</result>