Instructions: 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. How may I aid you? 
 customer: I am Linda Anderson. Owing to an emergency, I want to cancel my reservation. Can you help me? 
 agent: Sure, wait a minute. 
 customer: Ok. 
 agent: We found a reservation, shall I cancel it? 
 customer: Please cancel it. 
 agent: Your reservation has been cancelled. 
 customer: Thank you for your help. 
 agent: Thank you for opting us.
Output:
cancel