Detailed 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
Q: customer: Hi. 
 agent: Hello. How may I assist you today? 
 customer: My business meeting has been postponed, so I would like to change my existing reservation. 
 agent: Sure, I am here to help you to change that reservation but I need your name to proceed further. 
 customer: Ok, my name is Stephen Mitchell. 
 agent: I could not find any reservation with your name in our database. 
 customer: Ok, not an issues. Thank you for your help. 
 agent: My pleasure.
A:
no_reservation