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, I am Daniel Nelson. 
 agent: Hello, how can I be of your service? 
 customer: Can you please book a flight ticket from Washington, DC - DCA? 
 agent: Sure, may I know your destination airport code? 
 customer: I want to fly to Denver, CO - DEN. 
 agent: Please share your planned dates of travel. 
 customer: My trip dates are from 03/18 to 03/20. 
 agent: Let me know if you need any connection within your journey. 
 customer: Yes, I need a halt. 
 agent: Thank you for sharing your details. There are no flights available matching with your requirements. 
 customer: It's ok, not an issue. Thank you for your information. 
 agent: Thank you for reaching us.
no_flight