Teacher: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
Teacher: Now, understand the problem? Solve this instance: customer: Hello. 
 agent: Hello, how can I help you? 
 customer: I want to change my recent reservation, can you please help me with that? 
 agent: Sure, please provide me your name to check the reservation? 
 customer: Thomas Campbell here. 
 agent: Sorry, there is no reservation with your name. 
 customer: No problem, thank you for the information. 
 agent: Thank you for reaching us.
Student:
no_reservation