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

Ex Input:
customer: Hi. 
 agent: Hello, how may I assist you today? 
 customer: I need to book a flight ticket from IAD to OAK, Can you please help me for booking? 
 agent: Sure, may I know your good name please? 
 customer: Samuel Turner here. 
 agent: May I know on which dates you are willing to travel? 
 customer: I would like to travel on 02/12 to return on 02/14. 
 agent: May I know your class preference please? 
 customer: I am comfortable with any class. 
 agent: May I know your preferable time for journey? 
 customer: I would be return on morning. 
 agent: May I know your connection limit please? 
 customer: I need a connecting flight. 
 agent: There is a connecting flight of fare 300 with economy class in Frontier airline, shall I proceed for booking? 
 customer: Ok, proceed for booking. 
 agent: Your reservation has bee confirmed with flight number 1012, depart time is at 18:00 hours on Feb, 12 and return time is at 5:00 hours on Feb, 14. 
 customer: Thanks for your information. 
 agent: You are welcome.

Ex Output:
book


Ex Input:
customer: Hello. 
 agent: Hello. 
 customer: I am Jennifer Hall. 
 agent: How can I help you? 
 customer: I want to cancel my reservation, due to heavy rainfall in Seattle, can you help me? 
 agent: Yes, I can help you. 
 customer: Thank you. 
 agent: Sorry to inform you that there is no reservation found on your name. 
 customer: That's ok, thank you for your information. 
 agent: Thank you for contacting us.

Ex Output:
no_reservation


Ex Input:
customer: Hello. 
 agent: Hello, how may I assist you? 
 customer: Please cancel my active reservation as my meeting was cancelled. 
 agent: Sure, may I know your good name please? 
 customer: Lisa Smith. 
 agent: Please wait for a moment. 
 customer: Ok. 
 agent: Sorry, there is no reservation found on your name in our database to cancel. 
 customer: Ok, no problem. Thank you. 
 agent: Thank you for approaching us.

Ex Output:
no_reservation