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
Q: customer: Hello. 
 agent: Hello, how may I aid you today? 
 customer: Can you find me a flight from DEN to PHL? 
 agent: Sure, let me know your planned journey dates? 
 customer: I will fly on Dec 02 and return on Dec 04. 
 agent: Do you have any connection limit? 
 customer: I prefer a connecting flight. 
 agent: Is there any other specifications? 
 customer: I want my depart flight in morning. 
 agent: Can I know your good name? 
 customer: My name is Mark Jackson. 
 agent: Thanks for your details, there is no flight found on your desired journey locations. 
 customer: Ok, thank you for the information. 
 agent: Thank you.
A:
no_flight