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 can I aid you? 
 customer: I am Stephen Adams. Can you please help me to change my reservation? 
 agent: Sure, please wait. 
 customer: Ok. 
 agent: There is no reservation found with your name. 
 customer: Ok, no problem. Thank you. 
 agent: Have a good day.
no_reservation