Given the task definition and input, reply with output. 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: Hi, I am Jacob Robinson. 
 agent: Hello, How can I assist you? 
 customer: I would like to enjoy sky view observatory in Settle on 10/30. Can you make a return ticket reservation on 11/01? 
 agent: Sure, Please help me with your journey codes. 
 customer: Sure, I am heading towards Seattle SEA from MSP. 
 agent: Please wait a moment. 
 customer: Sure. 
 agent: Sorry, No flights found with your preferable dates. 
 customer: Ok, not an issue. Thank you for your assistance. 
 agent: Thank you for reaching us.
no_flight