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: Hi. 
 agent: Hello, how can I help you? 
 customer: I am Elizabeth Gonzalez. I am looking for a direct flight from IAH to DTW, please book my flight ticket. 
 agent: May I know your desired travel dates please? 
 customer: Sure, I want to depart on Dec 4th and I have to return back in the afternoon on Dec 6th. 
 agent: Please wait a while. 
 customer: Sure. 
 agent: There is a flight with connection limit 1 and fare 200, shall I proceed for booking? 
 customer: No, I prefer for a direct flight. 
 agent: Sorry to say, there is no flight available on your desired travel dates. 
 customer: Sad to hear that, thank you for checking. 
 agent: Thank you for opting us.

A: no_flight
****
Q: customer: Hi. 
 agent: Hello, welcome to flight booking agency. 
 customer: Myself Emma Thomas here. 
 agent: How may I guide you for today? 
 customer: I want to travel from AZ-PHX to CO-DEN, can you please help me to book a flight ticket? 
 agent: Sure, can you please share on what dates you are willing to travel? 
 customer: Sure, my planning of travel is from 03/30 to 04/01. 
 agent: Please give me a minute, I will look for the best airlines on this route. Sorry, there is no flight available on your requested dates. 
 customer: Ok, that's fine. 
 agent: Thank you for reaching us. 
 customer: Welcome. 
 agent: Have a great day.

A: no_flight
****
Q: customer: Hi. 
 agent: Hello, how may I help you today? 
 customer: I need to attend my parent's wedding anniversary on 05/26 in Washington DC - DCA, could you please help me to book my flight ticket. 
 agent: Sure, could you please provide your further details to proceed? 
 customer: OK. Actually I want to travel from Washington DC - DCA on 05/26 to Denver, CO - DEN. And my return date is on 05/28. Please make the booking with the name Anna Harris. 
 agent: OK, do you have any preference connections and price limit? 
 customer: Yes, price limit can be 1000 and connection must be one. 
 agent: OK, we are glad to inform you that we have found a flight on that day. details are as follows airline-Southwest flight number-1022 connection-1 and price is 100. Shall I proceed to booking? 
 customer: I am comfortable with this booking, you can proceed now. 
 agent: OK, your reservation has been done. 
 customer: Thank you. I am happy with your service. 
 agent: Your are welcome, thanks for contacting us. Have a great day ahead.

A:
book
****