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 assist you? 
 customer: I am Barbara Adams, can you book a ticket from PHL to DCA? 
 agent: Sure, may I know your travel dates please? 
 customer: I am planning to start on 12/16 and return on 12/18. 
 agent: Ok, hold on for a moment. Let me check the best flight for you. 
 customer: Make sure that connection limit is 1. 
 agent: I found a flight for you with JetBlue airline and it costs you 200. Shall I proceed? 
 customer: Please proceed. 
 agent: Your ticket has been confirmed with 1005 flight number. 
 customer: Thank you for booking. 
 agent: Welcome.
A:
book