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. 
 customer: Brian Walker here. 
 agent: How may I help you Brian? 
 customer: I want to attend a birthday party in New York. Will you please book my ticket? 
 agent: Ok, can you provide me New York airport code? 
 customer: Airport codes are SFO and LGA. 
 agent: May I know your travelling dates? 
 customer: I want to depart on 12/09 and return by 12/11. 
 agent: There is a flight with 1 connected flight which costs 200. Flight 1003 in AA airline. 
 customer: Ok, please proceed for booking. 
 agent: Shall I book it for you? Your booking is done. 
 customer: Thank you for your service. 
 agent: Thank you for choosing us.
book