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: Hello. 
 agent: Hello. 
 customer: I am Jack Miller. 
 agent: How may I assist you today? 
 customer: I am looking for a direct flight, could you please help me with booking a flight ticket with my requirement? 
 agent: Sure, may I know your travelling airport codes? 
 customer: I would like to travel from DTW to MSP. 
 agent: Please mention your travelling dates? 
 customer: I would like to depart on Apr 2nd and return on Apr 4th. 
 agent: Please wait a moment. 
 customer: Sure, take your time. And make sure that my airline is normal-cost. 
 agent: Sorry, there are no flight tickets available on your journey dates. 
 customer: Ok, not an issue. Anyways, thank you for the information. 
 agent: Thank you for reaching our service.
Output:
no_flight