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

Example Input: customer: Hi. 
 agent: Hello. How may I help you? 
 customer: Can you pleas check for the flights from Dec 21 to Dec 23. 
 agent: Sure, what are your trip source and destination? 
 customer: My airport codes are from ORD to DFW. 
 agent: Do you need any connections? 
 customer: Please check for 1 connecting flight. 
 agent: Are there any other preferences? 
 customer: I will be returning in afternoon with economy class. 
 agent: May I know your name? 
 customer: My name is Sandra King. 
 agent: Sorry, there is no flight found with your details. 
 customer: Oh! That's fine. Thank you for checking. 
 agent: Thank you for reaching us. 
 customer: Most welcome.
Example Output: no_flight

Example Input: customer: Hello. 
 agent: Hello. 
 customer: I am Elizabeth Walker. 
 agent: How may I assist you today? 
 customer: Will you please assist me in booking a flight ticket from ATL to CLT? 
 agent: Sure, may I know your travelling dates, please? 
 customer: I am planning to depart on June 07 and return on June 09. 
 agent: Do you need any specification? 
 customer: I need a halt in between my journey. 
 agent: Sorry, there are no flight tickets available on your journey dates. 
 customer: Ok, no problem. 
 agent: Thank you for reaching our service. 
 customer: Thank you for the information.
Example Output: no_flight

Example Input: customer: Hello. 
 agent: Hello, how may I help you? 
 customer: I want to travel from MCO to HOU, can you please help book a flight? 
 agent: Sure, may I know your travelling dates? 
 customer: My travelling dates are 01/12 and 01/14. 
 agent: Please give me a while. 
 customer: Ok. My connection limit should be 1. 
 agent: There is a flight available with Southwest airlines with 1 connection, shall I book it? 
 customer: Ok, proceed. 
 agent: Your ticket is confirmed, flight number is 1026. 
 customer: Thank you for booking. 
 agent: Thank you for reaching us, happy journey. Can I know your good name? 
 customer: My name is Donna Parker. 
 agent: Thank you, have a nice day? 
 customer: Welcome.
Example Output:
book