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. 
 customer: I am Sarah Jackson. 
 agent: How can I assist you, Sarah? 
 customer: Owing to an emergency, I would like to cancel my recent reservation. Can you help me with this? 
 agent: Sure, please wait for a minute. 
 customer: Sure, take your own time. 
 agent: I have successfully cancelled your reservation, Sarah. 
 customer: Thank you for your help. 
 agent: Thank you for contacting us.
Output:
cancel