You will be given a definition of a task first, then some input of the task.
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

customer: Hi. 
 agent: Hello. How can I assist you? 
 customer: Due to bad weather conditions, I cannot attend my meeting. Can you help me to change my existing reservation? 
 agent: Sure, may I know your name? 
 customer: Sure, my name is Frank Perez. 
 agent: Please give me a moment to check your ticket status. 
 customer: Ok. 
 agent: Sorry Frank, no reservation is available by your name. 
 customer: That's ok, thank you. 
 agent: Thank you for contacting us.
Output:
no_reservation