A call center agent has a list of 305 phone numbers of people in alphabetic…

A call center agent has a list of 305 phone numbers of people in alphabetic order of names (but she does not have any of the names). Needs to quickly contact Deepak Sharma to convey a message to him. If each call takes 2 minutes to complete, and every call is answered, what is the minimum amount of time in which she can guarantee to deliver the message to Mr Sharma.