The school opened computer classes and labor skills classes for students in the fourth grade. All the students in Class 4 and 1 actively signed up. Among them, 23 people signed up for computer classes, and 17 people signed up for labor skills classes. Statistics found that 5 Students participated in two courses at the same time. According to the above information, we can know how many students there are in Class 4 and Class 1.
学校为四年级的同学们开办了电脑课和劳技课，四1班的全体同学都积极地报名了，其中有23人报名参加电脑课，17人报名参加劳技课，经统计发现有5名同学同时参加了两门课，根据以上信息，可知四1班一共有多少名同学．
<gadget id="calculator">17 - 5</gadget>
<output>12</output>

<gadget id="calculator">23 + 12</gadget>
<output>35</output>

<result>35</result>