Given the task definition and input, reply with output. 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

customer: Hello. 
 agent: Hello. 
 customer: I am Katherine Harris. 
 agent: How can I help you Harris? 
 customer: I would like to cancel my reservation as I am leaving for an occasion, can you please help me out? 
 agent: Sure, I am here to help you. Please wait for a moment. 
 customer: Thank you. Sure, take your time. 
 agent: Sorry Harris, no reservation is available on your name. 
 customer: Ok no problem, thank you for your services. 
 agent: It's my pleasure, have a nice day.
no_reservation