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 can I aid you? 
 customer: I would like to meet my school friend at Boston, please help me in booking a ticket from PHX to BOS. 
 agent: Sure, can you please let me know your trip dates? 
 customer: My planned trip dates are on Oct 19 and Oct 21. 
 agent: Do you have any connection limit preference? 
 customer: I need a flight with single connection. 
 agent: Do you have any other specifications? 
 customer: No, thank you for asking. 
 agent: Could you help me with your name please? 
 customer: My name is Brian Lewis. 
 agent: American Airlines is having a single stopover with 1001 flight number and airfare is 200. Shall I proceed with this flight? 
 customer: Ok, please proceed for booking. 
 agent: For a economy class your ticket is booked. 
 customer: Thank you for your services. 
 agent: Thank you for reaching us.
A:
book