Detailed 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
Q: customer: Hello. 
 agent: Hello. How may I aid you today? 
 customer: Can you  please book a flight ticket from IAD to AUS? 
 agent: Sure, can you please share your preferable journey dates? 
 customer: Sure, I have planned my travel  dates as June 29 and July 01. 
 agent: May I know your name please? 
 customer: Sure, myself Barbara Phillips. 
 agent: Do you have any other specifications? 
 customer: I am looking for single connecting flight. 
 agent: I am sorry to say that there is no flight found under your details. 
 customer: Oh! It is sad to hear. Anyway, thank you for your time. 
 agent: Thank you for reaching us. 
 customer: Most welcome.
A:
no_flight