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: Steven Scott here. 
 agent: How may I aid you at this moment? 
 customer: I'm planning to meet my friend, please book a ticket from LAS to ORD. 
 agent: Sure, please share your travelling dates. 
 customer: Sure, my planned departure and return travel dates are 17th and 19th of January. 
 agent: Ok, do you need any lay by in between the journey? 
 customer: I'm looking for flights with 1 connection. 
 agent: Ok, may I know your class preference? 
 customer: I don't have any class preference but my depart time must be afternoon and return time must be evening. 
 agent: Ok, do you have any other preferences? 
 customer: No, I don't have any other specifications more than that. 
 agent: There are no flights found on your requested dates. 
 customer: That's ok, thank you for your information. 
 agent: Thank you for reaching us.
Output:
no_flight