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. 
 agent: Hello. How may I serve you? 
 customer: I want to book a flight ticket to Charlotte with price under 1000. can you please help me with booking a flight ticket? 
 agent: Sure, I am here to aid you. Can you mention the airport codes of both routes? 
 customer: Airport codes are LAX-CLT. 
 agent: May I have your name to proceed next? 
 customer: My name is Alexander Gonzalez. 
 agent: Please assign the dates of your travel to check with the flights. 
 customer: Travel dates are 05/02 and 05/04. 
 agent: Please wait for a minute, I will get back to you. 
 customer: OK. 
 agent: Thanks for waiting, but sorry to inform you that no flights in search on your respective routes. 
 customer: Ok, no issues. 
 agent: Thanks for choosing us, Have a nice day. 
 customer: Thanks for the help.
Output:
no_flight