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. I am William Jones. 
 agent: Hello, how may I help you today? 
 customer: Could you please help em to book a flight from DEN - DCA to meet my cousin? 
 agent: Sure, we are perky to help you. On which dates would you like me to book a flight ticket for you? 
 customer: My travel dates are 04/19 and 04/21. 
 agent: Do you need a lay by in between your journey? 
 customer: Yes, I need a halt in between the journey. 
 agent: Thank you for providing your details. 
 customer: Ok. 
 agent: We found a flight in UA airline has fare 100 matches given specifications. Shall I proceed for booking? 
 customer: Ok, please proceed. 
 agent: Your booking has been confirmed with flight number 1014. 
 customer: Thank you. 
 agent: Thank you for availing us.
Output:
book