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: Myself Mary Turner. 
 agent: What type of service you are excepting from us? 
 customer: Can you please cancel my existing reservation as there is a snow fall I can not move out and make the journey? 
 agent: Sure, I am here to help you. 
 customer: Thank you for assisting me. 
 agent: Please wait for a minute. Sorry fro the trouble, there is no reservation found on your name in our database. 
 customer: Ok, not a problem. Thank you for the information. 
 agent: Thank you for reaching us.
no_reservation