You will be given a definition of a task first, then some input of the task.
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

customer: Hello. 
 agent: Hello, how may I help you? 
 customer: I am George Hall, want to travel from IAH to SFO>. 
 agent: May I know your trip dates? 
 customer: My travel dates are from 06/05 to 06/07. Please check the flight with 1 connection. 
 agent: There is no reservation found under your name. 
 customer: It's ok, thank you. 
 agent: Most welcome.
Output:
no_flight