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. I am Raymond Miller. 
 agent: Hello, how can I provide assistance to you? 
 customer: Due to sudden change in my trip to another location, I would like to change my reservation. Can you please help me out? 
 agent: Sure, we are glad to help you. 
 customer: Thank you. 
 agent: Please wait a minute, I will check and let you know the status of your existing reservation. 
 customer: Sure, take your time. 
 agent: Thank you for waiting, sorry to notify you that there is no reservation matches with the given name. 
 customer: Ok, not an issue. Thank you for your kind information. 
 agent: Thank you for opting us.

Ex Output:
no_reservation


Ex Input:
customer: Hello. 
 agent: Hello. 
 customer: I am Sandra Evans. 
 agent: How can I assist you today? 
 customer: I want to change my travel dates in my previous reservation, can you please help me with that? 
 agent: Sure, please give me a moment. 
 customer: Ok. 
 agent: Thanks for waiting, there is no reservation found under your name. 
 customer: Oh! May be I am not booked my ticket properly at that time. Thank you for your service. 
 agent: Welcome, have a great day.

Ex Output:
no_reservation


Ex Input:
customer: Hello. 
 agent: Hello. How can I assist you at this moment? 
 customer: I am Sarah Thomas, can you help me to book a flight ticket from ATL to BOS? 
 agent: Sure, can you please provide your travelling dates? 
 customer: Ok, my depart date is 05/02 and return date is 05/04. 
 agent: Wait a moment please. 
 customer: Ok, take your own time. 
 agent: Spirit airlines is available on this route with a ticket fare of 100, shall I book your ticket? 
 customer: Please book it. 
 agent: Sarah Thomas, your ticket is booked with flight number 1007. 
 customer: Thank you for booking the flight with Spirit airlines. 
 agent: Thank you, have a safe journey.

Ex Output:
book