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. How may I assist you? 
 customer: I want to cancel my recent reservation, can you please help me with this? 
 agent: May I know your good name please? 
 customer: I am John Jackson. 
 agent: Please give me a moment. 
 customer: Sure. 
 agent: There is a reservation found with your given name. Shall I proceed with the cancellation? 
 customer: Ok, please cancel my booking. 
 agent: Your ticket has been cancelled. 
 customer: Thank you for your help. 
 agent: Thank you for choosing us.
cancel