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 book a ticket for me with my name Elizabeth Green? 
 agent: Sure, may I know airport codes? 
 customer: Thank you, my preferable locations are from PHX to DTW. 
 agent: May I know your trip dates? 
 customer: Sure, my planned dates are from 11/29 and 12/01. 
 agent: There is a flight for you with 1 connection. Shall I proceed? 
 customer: Please proceed. 
 agent: Your ticker is booked. 
 customer: Thanks for your response and great service. 
 agent: Most welcome.
Example Output: book

Example Input: customer: Hi. 
 agent: Hello. How can I assist you? 
 customer: Due to some issues, I am willing to change my existing reservation. Can you please help me for this? 
 agent: Sure, can I know your name please? 
 customer: I am Rebecca Lee. 
 agent: Ok, wait a moment please. 
 customer: Sure. 
 agent: Sorry, there is no reservation found on your name. 
 customer: Oh! It may not be booked properly due to some technical issues while booking. Thank you for checking. 
 agent: Thank you for approaching us.
Example Output: no_reservation

Example Input: customer: Hello. 
 agent: Hello. How can I assist you? 
 customer: I want to change my existing reservation, my music concert got postponed. Can you please help me out with that? 
 agent: Sure, let me know your name to check your reservation details. 
 customer: Thank you for accepting my request, I have done my reservation on the name of Gregory Williams. 
 agent: Thank you. Please wait for a while, let me check your reservation status. 
 customer: Sure, take your time. 
 agent: I am sorry to say you that there is no reservation found under your name in our database. 
 customer: Oh! I think the ticket was not booked properly while I am booking. Anyway, thank you for checking. 
 agent: Thank you for reaching us. 
 customer: Welcome.
Example Output:
no_reservation