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: Hello. 
 agent: Hello. How may I guide you today? 
 customer: Myself Nicholas Lee. I want to travel from HOU IAH locations, can you please help me in booking a flight ticket? 
 agent: I will help you with that, can you please share your journey dates? 
 customer: My travelling dates are from 08/15 and 08/17. 
 agent: I am sorry to say that there is no flight found. 
 customer: It's ok. Thank you for the information.
A:
no_flight