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 help you? 
 customer: I am Jason Parker. 
 agent: Ok. 
 customer: I need to attend farewell party in my college, could you please help me to book a flight ticket? 
 agent: Sure, will you provide your source and destination airport codes. 
 customer: My origin and destination airport codes are AUS and SEA. 
 agent: Will you provide your travelling dates? 
 customer: I planned to travel on 07/02 and 07/04. Please make sure that the connection is 1 and price limit is 200. 
 agent: Please give me a moment. 
 customer: Sure. 
 agent: Unfortunately there is no flights found under your required details. 
 customer: That's ok. Thank you for your information. 
 agent: Thank you for reaching us.Have a nice day.
Output:
no_flight