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 assist you? 
 customer: I'm Janet Thomas. I want to cancel my reservation, can you help me out? 
 agent: Sure, just wait a while to check. 
 customer: OK. 
 agent: Sorry Thomas, unfortunately there is no reservation found under your name in our database. 
 customer: Thank you for your immediate reply. 
 agent: Thank you, have a good day.
Output:
no_reservation