Teacher: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
Teacher: Now, understand the problem? Solve this instance: customer: Hello. 
 agent: Hello. How can I assist you today? 
 customer: I am Matthew Nelson. 
 agent: Glad to meet you Nelson. 
 customer: I am planning to book a ticket from DEN to OAK. Can you please help me out o book a ticket for me? 
 agent: Sure, I will help you with that. Can I have your travel dates please? 
 customer: I am planning to travel on 01/28 and return back on 01/30. 
 agent: Ok, please wait a moment. 
 customer: Sure. 
 agent: Yes, I have found a flight with connection 0 and price 100 in JetBlue airlines, is it ok for you? 
 customer: Can you check with connection 1. 
 agent: Sure, I will check with that. 
 customer: Ok. 
 agent: Sorry Nelson, no flight is available to you with connection 1. 
 customer: That's fine. Thank you for your help. 
 agent: My pleasure. Thank you for choosing us, have a great day.
Student:
no_flight