Detailed Instructions: 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
Q: customer: Hello. 
 agent: Hello. 
 customer: Andrew Green here. 
 agent: How may I assist you? 
 customer: I would like to travel from SFO to LAS. Can you please help me to book a ticket? 
 agent: Ok, please mention your travel dates too. 
 customer: My travelling dates will be on 11/05 to 11/07. 
 agent: There is a connecting flight-1024 on Spirit airlines with price 100, shall I book it? 
 customer: You can proceed to booking. 
 agent: Ok, ticket has been done with your name. 
 customer: Thank you. 
 agent: Thanks for choosing us.
A:
book