Query: user: I'm leaving soon and I need a round trip flight.
assistant: Ok, I just need more info. Where will you depart from? Where do you intend to go? When were you thinking to be back?
user: The city I'm reaching is London and the departing city is chi-town, I was thinking about be back on march 13th
assistant: do you also know the date you want to leave?
user: Yes, it's the 2nd
assistant: you have 3 trips to chose from. There's this american airlines flight leaving at 4:30 am and the return flight is scheduled to leave at 2:05 pm. The ticket costs $338.
user: I need to know the number of the stops.
assistant: Just 1
user: Explore the other options
assistant: You can travel with delta airlines and take off at 9:15 am, the return flight is scheduled to start at 8 am. The price to pay for the ticket is $305
user: I need to know the number of stops and the departing airport
assistant: Stops are just 1 and it will depart from o'hare international airport
user: this one can meet my necessities
assistant: I have the skills to buy tickets for you
user: How cool, yes, buy economy tickets please

Intent: Flights:ReserveRoundtripFlights