Q: 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 help you? 
 customer: I am Kenneth Thomas. My trip has been postponed, can you change my reservation? 
 agent: Sure, wait for a minute. 
 customer: Ok. 
 agent: Sorry Kenneth, no reservation found on your name. 
 customer: It's fine. 
 agent: Thank you for reaching us. 
 customer: Anyway, thank you for your information.
A:
no_reservation