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 can I aid you today? 
 customer: I am planning to visit Houston, can you please book me a ticket from ORD to HOU? 
 agent: Sure, we are here to help you. Can you share me your travelling dates? 
 customer: Thank you. My preferable journey dates are May 30 and June 01. 
 agent: May I know your name? 
 customer: My name is Samantha Edwards. 
 agent: Do you have any other specifications? 
 customer: I prefer connecting flight for this trip. 
 agent: Ok, wait for some time. 
 customer: Sure. 
 agent: Thanks for waiting there are no flights found on your details. 
 customer: Ok, not an issue. Thank you for providing information. 
 agent: Thanks for approaching us.
Output:
no_flight