For each origin city, find the destination city (or cities) with the longest direct flight. By direct flight, we mean a flight with no intermediate stops. Judge the longest flight in time, not distance. (15 points) Name the output columns origin_city, dest_city, and time representing the the flight time between them. Do not include duplicates of the same origin/destination city pair. Order the result by origin_city and then dest_city (ascending, i. e. alphabetically).