Definition: 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
Input: customer: Hi. 
 agent: Hello, what can I do for you at this moment? 
 customer: I am Andrew Johnson. I want to book a ticket to Denver, CO-DEN, can you please book me a ticket from Seattle, WA-SEA? 
 agent: Sure, on what dates you do need to book your ticket? 
 customer: My travel dates are from 05/10 to 05/12. 
 agent: Ok, let me check the availability of flights. 
 customer: Ok. 
 agent: Thank you for your time, there is a flight available in Spirit airline having single connection and you need to pay only 200. 
 customer: OK, please proceed for booking. 
 agent: Your booking has been done in flight 1007. 
 customer: Thank you. 
 agent: Thank you for choosing us.
Output:
book