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 may I be of your help? 
 customer: I just want to change an existing reservation due to my appointment with client got post pone. Can you help me? 
 agent: Sure, to proceed further may I know your good name please? 
 customer: I am Richard Miller. 
 agent: Ok, please wait a minute. 
 customer: Sure. 
 agent: Thank you for waiting. Unfortunately there is no reservation found by your name. 
 customer: Ok, no issue. Thank you. 
 agent: Thank you for opting us and have a good day.
no_reservation