Instructions: 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
Input: customer: Hello, I am Ryan Anderson. 
 agent: Hello, how may I aid you at this moment? 
 customer: I would like to go to a beach in Washington, so could you please book a ticket for me? 
 agent: Can I have your journey dates? 
 customer: I would like to go on 02/03 and return back on 02/05. 
 agent: Please send your nearby airport codes. 
 customer: My airport codes are PHX and DCA. 
 agent: Please wait for a moment. 
 customer: Ok, ensure it is a single connecting flight. 
 agent: Sorry, no flights are running on those dates. 
 customer: That's ok, thank you for checking. 
 agent: Thank you for reaching us. 
 customer: Welcome.
Output:
no_flight