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 can I aid you? 
 customer: I want to book a flight from DCA to visit PHX for vacation. Can you book a flight for me? 
 agent: May I know your trip dates? 
 customer: I will fly on Feb 19 and return on Feb 21. 
 agent: Do you have any connection limit preference? 
 customer: I prefer a direct flight. 
 agent: Do you have any other specifications? 
 customer: No. 
 agent:  Could you help me with your name please? 
 customer: My name is Joshua Green. 
 agent: Sorry, there is no direct flight available for the given dates. 
 customer: Ok, thank you for the information. 
 agent: Thank you for reaching us.
no_flight