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, How can I serve you? 
 customer: I am Carolyn Lopez. I want to enjoy Beach holidays at New York with my cousin. I want to book a ticket to LGA airport from Houston, HOU airport. 
 agent: Sure, Please help me with your travel dates. 
 customer: Sure, journey dates are 10/08 and 10/10. 
 agent: Please wait. 
 customer: Sure. 
 agent: Sorry, No flights found with your preferable dates. 
 customer: Ok, thanks for informing. 
 agent: Thank you for availing us.
Output:
no_flight