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. 
 agent: Hello, do you need any help from us? 
 customer: I am Gregory Thomas, want to cancel my reservation. Can you please help me? 
 agent: Sure, please allow me a moment. 
 customer: Sure. 
 agent: Thank you for waiting. Sorry, there is no reservation with your name in our portal to cancel further. 
 customer: That's fine, thank you. 
 agent: You are welcome.
Output:
no_reservation