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, I am William Wright. 
 agent: Hello, how may I oblige you today? 
 customer: Due to sudden changes my meeting has been postponed. I want to later my reservation. Can you please help me with it? 
 agent: Ok, please give me a moment. 
 customer: Ok. 
 agent: Unfortunately, there is no reservation found on your given name. 
 customer: Not an issue, thank you. 
 agent: Thank you.
Output:
no_reservation