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: Hi,. 
 agent: Hello, may I know your name please? 
 customer: I"m Dorothy Baker. 
 agent: How can I best serve you? 
 customer: Please cancel my recent reservation. 
 agent: Ok, please be on hold. 
 customer: Sure. 
 agent: Thanks for waiting. As you informed us to cancel your reservation, but there is no reservation found with your name. 
 customer: Thanks for the assistance. 
 agent: Thanks for reaching us, hope to serve you again. 
 customer: Thanks.
Student:
no_reservation