Definition: 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,. 
 agent: Hello, how may I assist you? 
 customer: I need to book a flight ticket to TX-DFW with a direct flight, so can you please help me out with this? 
 agent: Sure, may I know your journey dates? 
 customer: I want to start on 02/06 and return on 02/08. 
 agent: Can you share your origin airport code? 
 customer: My origin is Las Vegas, LAS. 
 agent: May I know your good name for further process? 
 customer: My name is John Baker. 
 agent: No flights found on your journey dates. 
 customer: Not a problem, thank you. 
 agent: Thank you for choosing us, have a nice day.
Output:
no_flight