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 serve you? 
 customer: Due to unapproved of my leaves of heavy work at office, I would like to cancel my ticket. Will you assist me in this? 
 agent: Sure. May I know your good name please? 
 customer: I am Sarah Jones. 
 agent: Ok, please wait for some time. 
 customer: Sure. 
 agent: Thanks for waiting, we found reservation on your name. 
 customer: Ok. 
 agent: Shall I cancel it? 
 customer: You can go ahead with cancellation. 
 agent: Ok, your reservation has been cancelled. 
 customer: Thank you. 
 agent: Thank you for opting us.
Student:
cancel