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: Hi,. 
 agent: Hello, How may I help you? 
 customer: I want to book a flight ticket with the name Mark Walker. 
 agent: Sure, Please help me with your journey details? 
 customer: I have planned to travel from Las Vegas, NV- LAS to Oakland, CA- OAK . Also my depart date is on 30th June  and return date is on  2nd July. 
 agent: OK, Do you have any other specifications? 
 customer: I don't have a connection limit but I have a price limit of 1000 and Airline preference as normal-cost. 
 agent: OK, Please wait I will revert you back in a while. 
 customer: OK, Sure. 
 agent: May I know your name? 
 customer: I have already mentioned my name. 
 agent: Sorry for the inconvinience. Thank you for being patience. Sorry, They were no flights available as per your requirement. 
 customer: OK, Thank you for your service.
Student:
no_flight