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 may I aid you today? 
 customer: Due to some emergency I need to cancel my recent reservation can you help me in cancelling my reservation? 
 agent: Sure. 
 customer: Thank you. 
 agent: Please send me your name. 
 customer: I am Brenda White. 
 agent: Thanks for providing your name. But no reservation is found in search. 
 customer: No problem. 
 agent: Thank you for choosing us. 
 customer: Thank you for the information.
Student:
no_reservation