Query: user: I would like economy flights for 9th of this month.
assistant: Where are you going and where are you leaving from?
user: I am going from Washington to Toronto, Ontario.
assistant: There are 2 possible flights. There is an American Airlines flighs leaving at 5:40 pm with 0 stops. the ticket costs $107.
user: Which airport will the flight arrive at?
assistant: The flight arrives at Toronto Pearson International Airport.
user: Can I refund the flight if need be and which airport does the flight leave from?
assistant: Sorry but the ticket is non refundable and the departure airport is Dulles International Airport.
user: That suits me well. Can you help me to buy flights for four people?

Intent: Flights:ReserveOnewayFlight