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: Hi. 
 agent: Hello. How can I aid you? 
 customer: I would like to attend live music concert at Charlotte, can you please reserve fight ticket from OAK to CLT? 
 agent: Sure, may I know the planned travel dates? 
 customer: Sure, my planned travelling dates are Jul, 31 and Aug, 02 respectively. 
 agent: Do you have any connection limit for this journey? 
 customer: I prefer for direct flight in my journey. 
 agent: Please provide me the name. 
 customer: John Scott here. 
 agent: Sorry, there are no flights are available for your desired intent. 
 customer: Ok, not an issue.Thank you for your information. 
 agent: Thank you for reaching us.

no_flight