Detailed Instructions: 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
Q: customer: Hi, I am Brian Taylor. 
 agent: Hello. How may I assist you? 
 customer: I need to book a flight ticket from PHX to LGA to enjoy Navajo adventure. Can you make a reservation with fare 5000? 
 agent: Sure, may I know your travel dates? 
 customer: Sure, my departure and arrival dates are Dec 29 and Dec 31. 
 agent: At what price range are you looking for? 
 customer: Already shared. 
 agent: We found a economy flight on your details with airline Frontier, flight number: 1016. Shall I book this ticket? 
 customer: Go ahead. 
 agent: Your ticket has been reserved. 
 customer: Thank you for your support. 
 agent: Thank you.
A:
no_flight