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. What can I do for you? 
 customer: Actually, I want to change my reservation because my trip got postponed. Can you help to cancel my flight ticket? 
 agent: Sure, I can help you with it. Before proceeding, may I know your name please? 
 customer: Myself Raymond Allen. 
 agent: Raymond, there is no reservation on your details. 
 customer: Oh! ok, thank you for the information. 
 agent: Welcome.
Output:
no_reservation