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 can I aid you? 
 customer: I am Frank Carter. I want to cancel my recent reservation, due to health issue. Can you help me in my cancellation? 
 agent: Sure, we are here to help you. 
 customer: Thank you. 
 agent: Please give me a moment to check your details and I will revert to you with the status. Sorry to inform you that there is no reservation exist on the name Frank Carter. 
 customer: Not an issue. Thank you for your kind information. 
 agent: Thank you for contacting us.
no_reservation