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. 
 agent: Hello, how may I assist you? 
 customer: I am Stephanie Carter. I want to book a flight ticket to visit Oakland Zoo at Oakland, could you help me in booking a flight ticket? 
 agent: Sure, may I know your journey dates? 
 customer: I would like to fly on 09/09 and return on 09/11. 
 agent: Kindly, mention your price limit. 
 customer: I can afford up to 500. 
 agent: May I know your airport codes? 
 customer: My source is Washington, DC - IAD and destination code is CA - OAK. 
 agent: Thank you for sharing your journey details with patience, please hold on. 
 customer: Sure, I need a direct flight. 
 agent: No flights found on your journey dates. 
 customer: Not an issue. Thank you. 
 agent: Thank you, have a nice day.
Output:
no_flight