You will be given a definition of a task first, then some input of the task.
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: Hi. I am Jack Robinson. 
 agent: Hello, How can I aid you? 
 customer: I want to book a flight ticket from MA-BOS to CO-DEN. Can you help me with this booking? 
 agent: Sure, I am here to help you. May I know your travelling dates? 
 customer: 04/12 and 04/14 are my travelling dates. 
 agent: Do you have any connection limit? 
 customer: I need a stop over. 
 agent: Thanks for your details,Please hold on. 
 customer: Ok. 
 agent: Thanks for waiting. There are no flights found on your data. 
 customer: No issue. Thank you. 
 agent: Thank you.
Output:
no_flight