There are 168 students participating in the summer camp. Divide them into several teams on average. Each team has no less than 10 people and no more than 30 people. How many different ways are there?
有168名学生参加夏令营，把他们平均分成若干队，每队的人数不少于10人，也不多于30人，有多少种不同的分法．
<result>5</result>