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
Q: customer: Hi, Paul Garcia here. 
 agent: Hello, how can I help you? 
 customer: Can you please reserve me a flight ticket which is having it's return time in the evening? 
 agent: Sure, we are happy to help you. When are you planning to make your journey? 
 customer: Thank you, my trip dates are 08/02 - 08/04. 
 agent: Please help me with your respective airport codes. 
 customer: My airport codes are SFO - DEN. 
 agent: Do you have any lay by in between journey? 
 customer: I need a direct flight. 
 agent: Is there specific depart and arrival timings for this trip? 
 customer: Already mentioned above. 
 agent: Do you have any other specifications? 
 customer: No, thank you for asking. 
 agent: Thanks for providing details, no flights are available on your journey routs. 
 customer: No issues, thank you. 
 agent: Thank you for choosing us.
A:
no_flight