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. 
 customer: My name is Dennis Collins. 
 agent: How may I assist you today? 
 customer: I'm planning a trip to Lake Austin in AUS with my friends, can you book a ticket from IAD? 
 agent: Sure, I will help you Dennis. May I know on which dates you planned to travel? 
 customer: The travel dates are from 03/31 to 04/02. 
 agent: Ok, please wait a moment to check the availability of flight and I will get back to you. 
 customer: Ok. 
 agent: Sorry for the inconvenience, no flights available as per your requested dates. 
 customer: No problem, thank you for your help. 
 agent: Thank you for contacting us, have a good day.
Student:
no_flight