Detailed Instructions: 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, how can I help you? 
 customer: Can you please book a flight ticket from JFK to DEN? 
 agent: Sure, I am here to help you. May I know your planned trip dates? 
 customer: Thank you, my travelling dates are Dec 30 and  Jan 01. 
 agent: Do you have any connection limit preference? 
 customer: Yes, I need a break in between the journey. 
 agent: Do you have any class preference? 
 customer: No, I am comfortable with any class. 
 agent: Are you looking for any time preference? 
 customer: Yes, I want to depart at evening. 
 agent: Do you have any other specifications? Could you help me with your name please? 
 customer: I am looking for normal cost airlines, can you please check for the Delta airlines? Yes, my name is Gregory Collins. 
 agent: I am sorry to say that there are no flights available on this route for the given dates. 
 customer: That's fine, thank you for the response. 
 agent: Thank you for reaching us.
A:
no_flight