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 help you today? 
 customer: My name is James White. I am planning to travel from SEA to OAK, could you please help me with booking a flight ticket? 
 agent: Can I know your dates of journey? 
 customer: My travelling dates are 01/16 and 01/18. 
 agent: Sorry James, I didn't find any flight basing on your details. 
 customer: That's really sad. Anyways, thank you for the information. 
 agent: You are welcome.
Student:
no_flight