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, I am Ryan Roberts. 
 agent: Hello, how can I assist you? 
 customer: I need to fly Austin for my brother's engagement, could you please help me in booking from JFK to AUS? 
 agent: Sure, when are you planning to travel? 
 customer: My journey is from 03/03 to 03/05. 
 agent: Please provide your specifications. 
 customer: I need a halt in mu journey. 
 agent: Unfortunately, there is no flights available based on your details. 
 customer: Ok, no worries. Thank you. 
 agent: Thank you.
Student:
no_flight