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 help you? 
 customer: I want to change my existing reservation due to heavy rainfall, can you please help me with that? 
 agent: Sure, can you provide me your name? 
 customer: My name is Samuel White. 
 agent: Give me a moment. 
 customer: Sure. 
 agent: Samuel White. I regret to inform that there is no reservation by your name. 
 customer: No problem, thank you. 
 agent: Thank you for reaching us.
no_reservation