Definition: 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
Input: customer: Hello. I am Mark Young. 
 agent: Hello, How can I serve you? 
 customer: I want to cancel my reservation, so please help me in the cancellation. 
 agent: Sure, Please wait a second. 
 customer: Ok. 
 agent: Sorry, No reservation found on your name. 
 customer: Not an issue. Thank you. 
 agent: Thank you for availing us.
Output:
no_reservation