Detailed Instructions: 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
Problem:customer: Hi. Nancy Taylor here. 
 agent: Hello, how can I guide you for today? 
 customer: I would like to book a ticket from SEA to BOS, please help me with that? 
 agent: Can you please share on what dates you are willing to travel? 
 customer: The travel dates are from 12/03 to 12/05. 
 agent: Please give me a minute, I will check the availability of flights on this route. 
 customer: Ok. 
 agent: Sorry, there are no flights available on your requested dates. 
 customer: That's ok, thank you for your help. 
 agent: Thank you for contacting us, have a nice day.3.
Solution:
no_flight