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. 
 agent: Hello, how may I guide you today? 
 customer: I am Stephen Turner, can you assist me to book a flight from DEN to ATL? 
 agent: Sure, could you please share me with your dates of trip? 
 customer: Ok, my travel date is on 01/07 from Denver and return date is on 01/09. 
 agent: Ok, please hold on for a mean while. The flight with the connecting flight of fare 100 has found, shall I book this ticket booking? 
 customer: Ok, please the book. 
 agent: The flight with the Delta airline and flight number is 1009 has been confirmed. 
 customer: Thank you for helping me with the booking. 
 agent: You are welcome and have a happy journey.
book

customer: Hello. 
 agent: Hello. How may I aid you? 
 customer: My name is William Lopez. Actually, I booked a ticket to NYC for a music concert but due to bad weather the trip is cancelled. 
 agent: Ok, so would you like me to change your existing reservation? 
 customer: Yes, help me out. 
 agent: Ok, please hold on for a moment. 
 customer: Sure, take your time. 
 agent: Sorry, I could not find any ticket booked with your name. 
 customer: That's ok. Thank you for your time. 
 agent: Thank you, have a great day.
no_reservation

customer: Hi. 
 agent: Hello. 
 customer: Brian Walker here. 
 agent: How may I help you Brian? 
 customer: I want to attend a birthday party in New York. Will you please book my ticket? 
 agent: Ok, can you provide me New York airport code? 
 customer: Airport codes are SFO and LGA. 
 agent: May I know your travelling dates? 
 customer: I want to depart on 12/09 and return by 12/11. 
 agent: There is a flight with 1 connected flight which costs 200. Flight 1003 in AA airline. 
 customer: Ok, please proceed for booking. 
 agent: Shall I book it for you? Your booking is done. 
 customer: Thank you for your service. 
 agent: Thank you for choosing us.
book