Teacher Wang wants to inform the students of all grades about something. Assuming that the notification is made by phone, it takes 1 minute for each person to be notified by calling. In the first minute, Teacher Wang notifies student A, and in the second minute, Teacher Wang notifies student B, and student A notifies C. In the third minute, Teacher Wang informs D, student A informs E, student B informs F, student C informs G, and so on. There are 127 students in the whole grade, how many minutes does it take to be notified?
王老师要向全年级同学们通知一件事，假定用电话通知，每打电话通知1人用1分钟，第一分钟王老师通知了A同学，第二分钟王老师通知B，A同学通知C，第三分钟王老师通知D，A同学通知E，B同学通知F，C同学通知G，依此类推．全年级共有127名同学，需要多少分钟通知完？
<result>7</result>