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: Hello, I am Robert Evans. 
 agent: Hello, how can I help you? 
 customer: My exams was postponed so I need to change my reservation, can you please help me to change my reservation? 
 agent: Sure, give me a minute. Thank you for waiting. 
 customer: Ok. 
 agent: I didn't find any reservation on your name. Thank you for connecting us. Have a safe day. 
 customer: Ok, not an issues.
A:
no_reservation