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 can I guide you? 
 customer: I am Carol Lewis. Due to my health problem I want to change my reservation, can you please help me to change my reservation? 
 agent: Sure, I will help you. Can you please give me a minute to check the ticket status? 
 customer: Sure, take your own time. 
 agent: Sorry Lewis, there is no reservation found with your name in our system database. 
 customer: That's fine. Thank you for your help. 
 agent: Thank you for choosing us.
Output:
no_reservation