Q: In this task, you are given a conversation between a flight agent and the customer. You are given 4 options and you need to select the goal of the conversation. It is provided as part of customer's context, which has to be one of the following: `book`: Make a new reservation, `cancel`: Cancel an existing reservation, `no_flight`: No flight found for the customer's preference, `no_reservation`: No reservation / No change / No cancellation was made in the conversation, mostly enquiring details
customer: Hello. 
 agent: Hello, how may I help you? 
 customer: I am Ronald Carter. I am planning to watch sports live events in Detroit, can you help me in booking a flight ticket within a price limit of 500? 
 agent: Sure, can I know your travelling dates? 
 customer: I will start on 12/26, return on 12/28. 
 agent: Ok, please help me with origin and destination airport codes? 
 customer: My source and destination airport codes are DC - DCA, MI - DTW. 
 agent: Delta airline is available with single connection and fare is 100. Shall I proceed? 
 customer: You can proceed to booking. 
 agent: Your ticket is booked with 1002 flight number in economy class. 
 customer: Thank you. 
 agent: Thank you for reaching us.
A:
book