Teacher: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
Teacher: Now, understand the problem? Solve this instance: customer: Hi. 
 agent: Hello. How can I assist you for the day? 
 customer: Find a flight for me from IAD to ATL. 
 agent: Sure, I will help you with that. May I know your travelling dates? 
 customer: Ok, my journey dates are from June 07 to 09. 
 agent: Do you have any class preference? 
 customer: No, I would like to depart in the evening. 
 agent: Can I know your connection limit? 
 customer: I need a direct flight. 
 agent: Sorry to say that, there is no direct flight on this route as per your travel dates. 
 customer: It's ok, thank you. 
 agent: May I know your name please? 
 customer: Ok, I am Ashley Walker. 
 agent: Thank you for giving the information,. 
 customer: Welcome. 
 agent: Have a great day.
Student:
no_flight