You will be given a definition of a task first, then some input of the task.
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

customer: Hello. 
 agent: Hello. How may I help you? 
 customer: Can you help me to book a flight ticket from HOU to DTW? 
 agent: Yes, can you tell me your dates of travel? 
 customer: My travel dates are Dec 22 and Dec 24. 
 agent: Do you have any other preferences? 
 customer: I would like to depart in the evening time and an connecting flight. 
 agent: Give me a moment. 
 customer: Sure. 
 agent: Sorry to inform you that there are no flights found on your requested dates. 
 customer: No problem, thank you for the information. 
 agent: Thank you for contacting us. Can I know your name? 
 customer: I am Amanda Thompson. 
 agent: Thank you.
Output:
no_flight