Definition: 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 Eric Clark. 
 agent: How can I help you at this moment? Glad to meet you Clark. 
 customer: I am looking to book a flight ticket from IAD to MSP. Can you please assist me? 
 agent: Please provide me your journey dates to search available flight for you. 
 customer: My travelling dates are 06/29 and 07/01. 
 agent: Sorry for this inconvenience, I could not find any flight with your details. 
 customer: It's ok, thank you for searching for the flight. 
 agent: It's my pleasure, have a great day ahead.
Output:
no_flight