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. 
 customer: My name is Elizabeth Wilson. 
 agent: How may I assist you? 
 customer: Can you please book a flight ticket with in the range of 200 from Seattle? 
 agent: Sure, may I know on which dates you would like to travel? 
 customer: Sure, 09/12 - 09/14 are my travelling dates. 
 agent: Help me with the airport codes? 
 customer: My source code is WA - SEA and destination code is Houston, TX - IAH. 
 agent: Sorry, we do not found any flights running in your given details. 
 customer: Ok, not a problem. Thank you. 
 agent: Thank you for reaching us.
Example Output: no_flight

Example Input: customer: Hello. I am Susan Jackson. 
 agent: Hello, how can I provide assistance for you? 
 customer: As I am racer, I want to attend for horse racing festival which is going to held at San Francisco, SFO. 
 agent: Ok. 
 customer: Can you please book a ticket from New York, LGA? 
 agent: Sure, I am perky to help you. 
 customer: Thank you. 
 agent: Let me know, when you are planning to depart? 
 customer: I want to start my journey on 10/16. 
 agent: Do you need a lay by in between your journey? 
 customer: I need a connecting flight. 
 agent: Kindly, share your return date of journey to proceed further. 
 customer: I will return back on 10/18. 
 agent: Thank you for sharing your details. Please, wait for a while. 
 customer: Sure. 
 agent: Thank you for being patience, there is a flight available in Southwest airline, flight number 1001 having fare 200 and a lay by. 
 customer: You can proceed. 
 agent: Your reservation has been processed. 
 customer: Thank you. 
 agent: Thank you for availing us.
Example Output: book

Example Input: customer: Hi. 
 agent: Hello, How can I help you? 
 customer: Can you help me to book a flight from LAS to AUS? 
 agent: Sure, May I know the travelling dates? 
 customer: My travelling dates are 11/29 and 12/01. 
 agent: Do you have any connection limit? 
 customer: I need a connecting flight. 
 agent: Do you have any preference in airline? 
 customer: I prefer normal cost airline. 
 agent: May I know your name? 
 customer: My name is Pamela Wilson. 
 agent: Please wait a minute. 
 customer: Ok. 
 agent: Sorry, No flights found with your chosen dates. 
 customer: No issues, thank you for your time. 
 agent: Thank you for opting us.
Example Output:
no_flight