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. 
 agent: Hello. 
 customer: I am Andrew Collins. 
 agent: How may I help you now? 
 customer: I want to book  a flight ticket to visit 16th street mall to buy accessories for my sister's marriage at CO-DEN. 
 agent: Ok, please mention your travel dates? 
 customer: 11/11 and 11/13 are my preferable travelling dates. 
 agent: Ok, mention your origin airport code? 
 customer:  I would like to start from NC-CLT. 
 agent: Sorry, no flights are available with your criteria. 
 customer: No issue. 
 agent: Thanks for reaching us, have a nice day. 
 customer: Thank you for your service.
Solution:
no_flight