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: Hi. 
 agent: Hello. How may I aid you? 
 customer: Can you please help me in cancelling my recent my reservation? 
 agent: Sure, I am glad to help you. 
 customer: Thank you. 
 agent: May I know your name? 
 customer: I am Katherine Thompson. 
 agent: I found your reservation and cancelled it successfully. 
 customer: Thank you.
cancel