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: Hello. 
 agent: Hello. How may I assist you now? 
 customer: Can you aid me to book my ticket from DEN to HOU? 
 agent: Ok, may I know your planned dates for this journey? 
 customer: My travel dates are Nov 5 and Nov 7 respectively. 
 agent: May I know your good name please? 
 customer: Gary Scott here. 
 agent: May I know your specifications? 
 customer: Make sure that connection limit is single. 
 agent: Gary Scott, there is o flight currently available for your journey. Thank you for approaching us. 
 customer: No issue. 
 agent: Have a nice day.
A:
no_flight