There are 18 players in a summer swimming training camp. One day, the coach has an urgent matter and needs to notify each player as soon as possible to stop training for one day. If one person is notified every minute by phone, how long will it take at least to notify all team members? (Please explain in your preferred way)
一个暑期游泳训练营有18个队员，一天教练有急事，需尽快通知到每一个队员停训一天．如果用打电话的方式，每分钟通知一人，问至少需多少分钟才能通知到所有的队员？(请你用你喜欢的方法加以说明)
<result>5</result>