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 Pamela Walker. 
 agent: Hello, how may I serve you now? 
 customer: I want to visit my brother home town in San Francisco, can you help me with reservation? 
 agent: Sure, I can make your reservation right now. Can you please provide me your airport codes? 
 customer: My origin is LAS and destination is SFO. 
 agent: Do you need any halt in between your journey? 
 customer: Yes, I need flight with single halt. 
 agent: May I know your travelling dates? 
 customer: My depart is on 04/15 and return on 04/17. 
 agent: Is there any price limit for you? 
 customer: My price limit is 200. 
 agent: Ok, please wait a moment. 
 customer: OK. 
 agent: Unfortunately, there is no flight found on your journey details. 
 customer: No problem, I will try with another airline. Thank you for the information. 
 agent: Thanks for approaching us and have a great day.
Output:
no_flight