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
Input: customer: Hello. 
 agent: Hello, how may I support you today? 
 customer: I am planning to attend music concert at DCA, can you please help me with booking a flight ticket from EWR? 
 agent: Sure, please share me your journey dates. 
 customer: I would like to take off on Mar 28 and return on Mar 30. 
 agent:  Do you have any connection limit? 
 customer: I am looking for a connecting flight. 
 agent:  Can I know your good name please? 
 customer: My name is Brian Wright. 
 agent: Are there any other specifications? 
 customer: I would like to depart during afternoon time. 
 agent: Sorry to say that, there are no flights available on the routes of your journey. 
 customer: Ok, no issues. Thank you for the information. 
 agent: Thank you for opting us. 
 customer: You are welcome.
Output:
no_flight