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: 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. Frank Edwards here. 
 agent: Hello Frank, how may I aid you? 
 customer: Due to an emergency, I want to cancel my reservation. Can you please help me for that? 
 agent: Sure, wait a moment to check your previous reservation status. 
 customer: Ok. 
 agent: Sorry Frank, we don't found any reservation under your name. Would you like to ask us anything else? 
 customer: Nothing, thank you for the information. 
 agent: Ok, thank you for reaching us, have a nice day.

A: no_reservation
****
Q: customer: Hello, my name is Katherine Miller. 
 agent: Hello, Katherine Miller. How can I assist you? 
 customer: I am planning to spend my vacation holidays with my brother, so I need to make a flight reservation. 
 agent: OK, what is your exact destination and when do you want to go? 
 customer: My destination airport is PA-PHL, and my travelling dates are departure on 03/20 and arrival on 03/22. 
 agent: Let me know your source point. 
 customer: My source airport is San Francisco, CA-SFO. 
 agent: Sorry to inform, no flights are found regarding to your specifications. 
 customer: That's not a problem, thanks for your information. 
 agent: Thanks for choosing us. Have a great day.

A:
no_flight
****