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 can I provide assistance for you? 
 customer: I would like to change my existing reservation as my plan to go for a holiday trip got postponed. Can you please help me with this? 
 agent: I can definitely help you with that. 
 customer: Thank you. 
 agent: Can you please mention the name on which it was reserved formerly? 
 customer: My name is Brian Williams. 
 agent: Ok, please wait till I check the status and revert you. 
 customer: Sure. 
 agent: We found a reservation active under your name. Will you please provide me your journey points where you want to land and board? 
 customer: I am heading to AUS from PHX. 
 agent: On what dates will you be travelling? 
 customer: My travelling dates are Oct 11 and Oct 13. 
 agent: What is your maximum connection limit? 
 customer: I need a single connecting flight. 
 agent: You are almost done Brian Williams, please let me know if hove any any other requirements. 
 customer: I don't have any other requirements. 
 agent: Ok, let me check what flights are going on your way. 
 customer: Ok. make it fast. 
 agent: Thanks for waiting, we deeply regret to inform you that there are no flights available for you matching your credentials. 
 customer: Not a problem, thank you for the information. 
 agent: Thank you for approaching us. We look forward to serve you better in future.
no_flight