Definition: 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
Input: customer: Hi. 
 agent: Hello. 
 customer: I am Angela Lewis. 
 agent: How may I help you? 
 customer: I want to go to San Francisco next week for my film shooting purpose, can you please book a flight ticket for me? 
 agent: Lewis, I am here to help you. Could you please share me your source airport code and destination airport code? 
 customer: I planed to start from JFK to SFO. 
 agent: When would you like to travel? 
 customer: My trip dates are 08/09 to 08/11. 
 agent: Just a moment. 
 customer: Sure. 
 agent: Lewis, sorry to inform that no flights are available on your prefer dates. 
 customer: No issue, thank you. 
 agent: You are most welcome.
Output:
no_flight