Instructions: 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
Input: customer: Hello. 
 agent: Hello. How may I help you? 
 customer: Myself Justin Wright from Orlando. I have to go to Washington next month for my film shooting purpose. Can you please book a flight ticket from MCO to DCA? 
 agent: May I know your travel dates? 
 customer: Thank you for your positive response, I want to departure on 01/27 and please confirm my return ticket also on 01/29. 
 agent: Sorry for this inconvenience, I could not find any flight with your requirements. 
 customer: Oh! It's ok no problem. Thank you for your information. 
 agent: Thank you for reaching us.
Output:
no_flight