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? If you are still confused, see the following example:
customer: Hi. 
 agent: Hello. How can I help you? 
 customer: I would like to change my existing reservation as my plan to go for a holiday trip got postponed. Can you please help me with this? 
 agent: Sure, may I know your name please? 
 customer: My name is Anthony Phillips. 
 agent: Please wait a moment. 
 customer: Sure. 
 agent: Unfortunately there is no reservation found with your given name. 
 customer: Not a problem, thank you for checking. 
 agent: Thank you for choosing us.
Solution: no_reservation
Reason: Here the customer has not asked for any booking, he just wanted to update his already booked flight, so the status would be no_reservation

Now, solve this instance: customer: Hello. 
 agent: Hello. 
 customer: I am Donald Collins. 
 agent: How can I help you? 
 customer: I am planning to book a ticket from LAX to IAH. Can you please help me out? 
 agent: Sure, may I know your travel dates please? 
 customer: I would like to travel on 04/21 and return back on 04/23. 
 agent: Ok, do you have any other specifications? 
 customer: My connection limit is 1. 
 agent: Please be on hold. 
 customer: Sure. 
 agent: I have searched for the flights with your details but unfortunately there are no flights available for you. 
 customer: Yes, you can proceed the booking. That's fine. Thank you. 
 agent: Thank you for choosing us.
Student:
no_flight