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

Ex Input:
customer: Hi, I am Gregory Johnson. 
 agent: Hello, how may I render you? 
 customer: I want to reach New York, NY - EWR, to meet my cousin on her birthday. 
 agent: Ok. 
 customer: Can you help me with reserving a flight ticket within range 1000? 
 agent: Sure, we are pleased to serve you. May I know your boarding point? 
 customer: I want to board from Austin, TX - AUS. 
 agent: When did you planned to travel? 
 customer: I have planned to travel on 02/12 and return on 12/14. 
 agent: Please wait for a while. 
 customer: Sure. 
 agent: Thank you for waiting, we are sorry to inform you that no flights were available based on your schedule. 
 customer: Ok, not a problem. Thanks for your kind help. 
 agent: Thank you for reaching us.

Ex Output:
no_flight


Ex Input:
customer: Hello, I am Richard Jones. 
 agent: Hello, how can I support you? 
 customer: Could you please help me with booking a flight to Seattle, SEA from New York, LGA? 
 agent: Sur, can you help me with your journey dates? 
 customer: I want to attend my sister's marriage, so you can book a ticket on 02/17 and return on 02/19. 
 agent: Sorry, no flights found on your given preferences. 
 customer: No problem, thank you for the information. 
 agent: Thank you for reaching us.

Ex Output:
no_flight


Ex Input:
customer: Hello. 
 agent: Hello, how can I assist you? 
 customer: Please book a ticket from Phoenix, AZ-PHX to Washington DC-IAD. 
 agent: Sure, please share your travelling dates. 
 customer: Depart date is 01/12 and 01/14 is return. 
 agent: We found a flight with single connection and price is 100 of 1016 flight. Shall I proceed for booking? 
 customer: Please book a flight. 
 agent: Your ticket has been confirmed with UA airlines. 
 customer: Thanks. 
 agent: May I know your name? 
 customer: My name is Melissa Walker. 
 agent: Thank you. 
 customer: Thanks.

Ex Output:
book