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, welcome to flight booking agency. 
 customer: Myself Emma Thomas here. 
 agent: How may I guide you for today? 
 customer: I want to travel from AZ-PHX to CO-DEN, can you please help me to book a flight ticket? 
 agent: Sure, can you please share on what dates you are willing to travel? 
 customer: Sure, my planning of travel is from 03/30 to 04/01. 
 agent: Please give me a minute, I will look for the best airlines on this route. Sorry, there is no flight available on your requested dates. 
 customer: Ok, that's fine. 
 agent: Thank you for reaching us. 
 customer: Welcome. 
 agent: Have a great day.
Student:
no_flight