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 assist you now? 
 customer: Can you please reserve me a flight ticket from SFO to BOS? 
 agent: Sure, I will help you with booking, please mention your good name? 
 customer: I am Shirley Allen. 
 agent: Please share me your planned journey dates? 
 customer: My journey dates are Mar 05 and Mar 07. 
 agent: Do you want a connecting flight? 
 customer: Yes, I need a connecting flight. 
 agent: Is there any other requirement? 
 customer: No. 
 agent: Thank you for the details, sorry there is no flight available on your given journey data. 
 customer: Ok, no issues. Thank you for your information. 
 agent: Thank you for visiting us, have a nice day ahead.
Output:
no_flight