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, I am Carol Edwards. 
 agent: Hello, how may I help you at this moment? 
 customer: I would like to go to a Olympic National Park in Washington, so could you please book a ticket for me? 
 agent: Can I have your journey dates? 
 customer: I would like to go on 05/20 and return back on 05/22. 
 agent: Please send your airport codes. 
 customer: My source and destination airport codes are LAX and IAD. 
 agent: Please wait for a moment. 
 customer: Ok, ensure it is a single connecting flight. 
 agent: There is a flight available with UA airlines, shall I book it? 
 customer: Ok, please proceed for booking. 
 agent: Your booking is done with flight number 1007. 
 customer: Thank you. 
 agent: Thank you for reaching us. Have a nice day. 
 customer: Welcome.
A:
book