Detailed 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
Problem:customer: Hi. Ryan Evans here. 
 agent: Hello. How can I support you? 
 customer: Can you please reserve me a flight ticket from DTW to OAK? 
 agent: Sure, to book a ticket may I know when would you like to travel? 
 customer: My trip dates are 06/14 - 06/16. 
 agent: Do you have any connection limit in between journey? 
 customer: I need a single connection. 
 agent: Is there any other requirements? 
 customer: My depart time should be in the evening. 
 agent: Can you please share me your name? 
 customer: Already mentioned above. 
 agent: Unfortunately there is no flight found with your matching details. 
 customer: No issues, thank you. 
 agent: Thank you.
Solution:
no_flight