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 Jessica Evens. 
 agent: Hello,. How may I serve you? 
 customer: I want to book a flight ticket on  01/04 to 01/06 for which I have a exam at IAH. 
 agent: Sure, may I know your origin point? 
 customer: My source code is ATL. And I want with 1 connection. 
 agent: Sorry to inform that there is no flight found with your specification. 
 customer: Ok. Thank you for  information and your service. 
 agent: Thank you for reaching us.
Output:
no_flight