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: Hello. 
 agent: Hello, how may I give assistance to you? 
 customer: I want to change my reservation as my exams got preponed, can you please help me? 
 agent: Sure, may I know your name? 
 customer: I am Brandon Turner. 
 agent: Please wait a minute. 
 customer: Ok. 
 agent: There is a no reservation found on your name. 
 customer: Ok, thanks for the information. 
 agent: Thank you for availing our agency.
Output:
no_reservation