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 help you today? 
 customer: Can you please help me in changing my existing reservation, as my football match got postponed to some other date. 
 agent: Sure, may I know your name? 
 customer: Brain Anderson here. 
 agent: Please hold a moment, let me check with your details. 
 customer: Sure. 
 agent: Sorry, there are no active reservations on your name to change. 
 customer: No problem, thanks for your information. 
 agent: Thank you for choosing our service.
no_reservation