You will be given a definition of a task first, then some input of the task.
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

customer: Hi. 
 agent: Hello, how may I aid you at this moment? 
 customer: I would like to change my existing reservation, can you please help me in changing? 
 agent: Sure, we are here to help you. May I know your good name? 
 customer: Anthony Thomas. 
 agent: Ok, please wait for a minute. 
 customer: Sure. 
 agent: Thanks for waiting, there is no active reservation found on your name. 
 customer: Ok, not an issue. Thank you. 
 agent: Thank you for choosing us.
Output:
no_reservation