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  help you? 
 customer: Carol Lopez here. I want to cancel my recent reservation, can you please help me out? 
 agent: Ok, just a moment please. 
 customer: Ok, take your own time. 
 agent: I am sorry no reservation found on your name. 
 customer: That's ok. Thank you for your service. 
 agent: Thank you for choosing us.
Student:
no_reservation