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. How may I help you? 
 customer: Please book a ticket from Oakland, CA-OAK to Austin, TX-AUS. 
 agent: Ok, on which dates you are willing to travel? 
 customer: My travelling dates are from 04/14 to 04/16. 
 agent: May I know your name for further use? 
 customer: Sure. I am Paul Green. 
 agent: There is a direct flight-1015 with price 100, shall I proceed? 
 customer: Please do not book direct flight. 
 agent: Would you like me to search a flight with single connection? 
 customer: Please search a flight with single connection. 
 agent: Sorry, there is no flight with single connection. Thanks for reaching us, have a good day. 
 customer: Thank you.
Output:
no_flight