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: Hi. 
 agent: Hello, how may I help you today? 
 customer: Owing to an emergency I want to cancel my reservation, can you help me? 
 agent: Sure, I am here to help you with this. May I know your name please? 
 customer: Myself Sarah Campbell. 
 agent: Ok, please wait for a moment. 
 customer: Sure, I will wait for your response. 
 agent: Sorry Sarah, there is no reservation found as per your name to cancel it. 
 customer: No problem, thanks for checking. 
 agent: You are welcome always.
Student:
no_reservation