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 guide you for today? 
 customer: I'm Michelle Adams. I am planning to attend music concert at SFO, can you please help me with booking a flight ticket from PHX? 
 agent: Can you please share on what dates you are willing to travel? 
 customer: Sure, I would like to take off on 05/01 and return back on 05/03. 
 agent: Please give me a minute. 
 customer: Sure. 
 agent: Sorry, there are no flights available on your requested dates. 
 customer: Ok, no issues. Thank you for checking. 
 agent: Thank you for contacting us, have a nice day. 
 customer: You are welcome.
Student:
no_flight