The teacher first informs two students to gather at the school, and then the two students notify two students at the same time, and so on, and then each informs two students. If it takes 2 minutes to notify two students, then it takes 14 minutes to notify 14 students. how many minutes.
老师先通知两名同学到学校集合，这两名同学再分别同时通知两名同学，依此类推，每人再通知两名同学，如果每通知两人共需2分钟，那么通知14名同学需要多少分钟．
<result>8</result>