Teacher: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
Teacher: Now, understand the problem? Solve this instance: customer: Hello,. 
 agent: Hello, How can I support you? 
 customer: I am Ryan Roberts, I want to cancel my recent reservation as our trip got postponed. Please help me out. 
 agent: Sure. I regret to inform you that there is no reservation found with your name. 
 customer: No issues, thank you the information. 
 agent: Ok, Than you.
Student:
no_reservation