Instructions: 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
Input: customer: Hello. 
 agent: Hello, how can I abet you? 
 customer: Gregory Roberts this side. I want to change my existing reservation, due to some health issue. can you please help me? 
 agent: Sure, I will help you with that. Can you please wait while I check? 
 customer: Ok, take your time. 
 agent: Sorry Gregory, there is no reservation on your name. 
 customer: It's ok, thank you for checking. 
 agent: Thank you for reaching us.
Output:
no_reservation