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

Example input: customer: Hi. 
 agent: Hello. How can I help you? 
 customer: I would like to change my existing reservation as my plan to go for a holiday trip got postponed. Can you please help me with this? 
 agent: Sure, may I know your name please? 
 customer: My name is Anthony Phillips. 
 agent: Please wait a moment. 
 customer: Sure. 
 agent: Unfortunately there is no reservation found with your given name. 
 customer: Not a problem, thank you for checking. 
 agent: Thank you for choosing us.
Example output: no_reservation
Example explanation: Here the customer has not asked for any booking, he just wanted to update his already booked flight, so the status would be no_reservation
Q: customer: Hello, I am Samuel Hall from Las Vegas. 
 agent: Hello, how may I help you at this moment? 
 customer: I need to attend an conference meeting at Philadelphia, PA-PHL. So can you please help me in booking a ticket within fare of 200? 
 agent: Sure, I will aid you. Please send your travelling dates. 
 customer: My travelling dates are from 06/24 to 06/26. 
 agent: Noted. Can I have your source airport code? 
 customer: My boarding airport code is NV-LAS. 
 agent: There is a connecting flight available with Spirit airline, shall I book it? 
 customer: I don't want Spirit airline, can you please check for any another airline for me? 
 agent: Yes, Hawaiian airline is also providing service on your route. Shall I proceed? 
 customer: That's perfect airline for me, please proceed for booking. 
 agent: Your booking is done with flight number 1007. Happy journey. 
 customer: Thanks for your extendable customer support in booking. 
 agent: You are welcome. Thank you for reaching us, have a nice day.
A:
book