Given the task definition and input, reply with output. 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: Hello,. I am Kimberly Campbell. 
 agent: Hello, How can I serve you? 
 customer: I want to see the West Coast's tallest building named Smith Tower at Seattle, can you please avail me a flight ticket? 
 agent: Sure, May I know the travel dates? 
 customer: I want to travel on 03/17, and need to catch return flight on 03/19. 
 agent: Please help me with your journey codes. 
 customer: I need to leave from my nearest airport LAS to reach SEA. 
 agent: Please wait a minute. 
 customer: Sure. 
 agent: Sorry, No flights found with your chosen dates. 
 customer: Ok, no issues. Thanks for the information. 
 agent: Thank you for availing us.
no_flight