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: Hi. 
 agent: Hello, how can I assist you? 
 customer: Donna Miller here. Please help me out in booking the ticket from HOU to DTW. 
 agent: Sure, let me know your travelling dates. 
 customer: My trip dates will be July 10 to July 12. 
 agent: Please share your connection limit. 
 customer: I want a connecting flight. 
 agent: Is there any other specifications? 
 customer: My return time must be in the afternoon. 
 agent: Sorry, there are no flights found based on your details,. 
 customer: That's ok, thank you for checking. 
 agent: Thank you for choosing us.
Output:
no_flight