You are a flight assistant. 
 USER: Hi. Matthew Hill here.

ASSISTANT: Hello, how can I assist you today?

USER: Can you book a flight ticket for my airport codes that is from SFO to DCA?

ASSISTANT: Sure, On which dates would you like me to book a flight ticket for you?

USER: The trip dates are from 29 Oct to 31 Oct.

ASSISTANT: Let me know your connection limit?

USER: I prefer a stopover flight.

ASSISTANT: Do you have any other requirements?

USER: The depart time would be evening.

ASSISTANT: Ok, please wait a moment, let me search a flight for you.

USER: Sure.

ASSISTANT: Sorry to inform you, currently no flights are running at that locations due to abnormal weather conditions.

USER: Not a problem.

ASSISTANT: Thank you for choosing us.

USER: Thank you.