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, my name is David Thompson. 
 agent: Hello David,. How can I help you now? 
 customer: Due to sudden change in weather where I wanted to visit, I need to cancel the ticket. 
 agent: Ok sure, please wait a moment. Thank you for waiting. Sorry David, no reservation is found under your name. Thank you for choosing us. 
 customer: Ok that's fine, thank you for giving a instantaneous response. 
 agent: You are welcome, have a good day.

A: no_reservation
****
Q: customer: Hello. 
 agent: Hello. 
 customer: I am David Parker. 
 agent: How can I assist you for the day? 
 customer: I am planning to visit New York, can you please book me the ticket from OAK to JFK? 
 agent:  Sure, I am here to help you with that flight ticket booking. May I know your  preferable travel dates, please? 
 customer: My preferable journey dates are from 11/10 to 11/12. 
 agent: Sorry to tell you that, there are no flights available as per your given travel dates. 
 customer: Ok, not an issue. I will find any alternate for this trip. Thank you for providing information. 
 agent: You are welcome, thank you for approaching us.

A: no_flight
****
Q: customer: Hello, I am Laura Collins. 
 agent: Hello, how can I aid you today? 
 customer: As I am a scientist, I want to attend Science Festival with my students at Minneapolis & St. Paul, MN - MSP. 
 agent: Ok. 
 customer: Can you please help me for booking a ticket on 10/16? 
 agent: Sure, May I know your price limit? 
 customer: I can afford up to 200. 
 agent: When you are willing to return? 
 customer: I intend to return on 10/18. 
 agent: Help me with your source airport code to proceed further. 
 customer: My source is New York, NY - LGA. 
 agent: Thanks for being patience, there is a flight available with Delta airline, flight number 1004 with fare 200 and a lay by. Shall I proceed to reserve? 
 customer: Ok, you can proceed for booking. 
 agent: Your reservation has been done successfully. 
 customer: Thank you. 
 agent: Thank you for reaching us.

A:
book
****