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 can I assist you? 
 customer: My name is Jacob Miller. I would like to visit Phoenix. Can you help me for booking a flight ticket from ATL to PHX? 
 agent: Sure, I can assist you and can you please mention your travelling dates? 
 customer: My travelling dates are Aug 09 and Aug 11. 
 agent: Do you have any other specifications? 
 customer: I need a direct flight in my journey. 
 agent: Please allow me a moment. Sorry for the trouble, there is no flight obtained on your journey dates to book a flight ticket. 
 customer: That's ok, thank you for checking. 
 agent: You are most welcome and thank you for reaching us.
Output:
no_flight