instruction: list all round trip flights from INDIANAPOLIS to ORLANDO departing either on 12 27 or on 12 28
response: SELECT DISTINCT flight.flight_id FROM airport_service AS AIRPORT_SERVICE_0, airport_service AS AIRPORT_SERVICE_1, city AS CITY_0, city AS CITY_1, date_day AS DATE_DAY_0, date_day AS DATE_DAY_1, days AS DAYS_0, days AS DAYS_1, fare AS FARE_0, fare AS FARE_1, fare_basis, flight, flight_fare AS FLIGHT_FARE_0, flight_fare AS FLIGHT_FARE_1 WHERE ((((DATE_DAY_0.day_number = 27 AND DATE_DAY_0.month_number = 12 AND DATE_DAY_0.year = 1991 AND DATE_DAY_1.day_number = 27 AND DATE_DAY_1.month_number = 12 AND DATE_DAY_1.year = 1991 AND DAYS_0.day_name = DATE_DAY_0.day_name AND DAYS_1.day_name = DATE_DAY_1.day_name AND fare_basis.basis_days = DAYS_1.days_code AND FARE_0.fare_basis_code = fare_basis.fare_basis_code AND NOT FARE_0.round_trip_cost IS NULL AND FLIGHT_FARE_0.fare_id = FARE_0.fare_id AND flight.flight_days = DAYS_0.days_code AND flight.flight_id = FLIGHT_FARE_0.flight_id) OR (DATE_DAY_0.day_number = 28 AND DATE_DAY_0.month_number = 12 AND DATE_DAY_0.year = 1991 AND DATE_DAY_1.day_number = 28 AND DATE_DAY_1.month_number = 12 AND DATE_DAY_1.year = 1991 AND DAYS_0.day_name = DATE_DAY_0.day_name AND DAYS_1.day_name = DATE_DAY_1.day_name AND fare_basis.basis_days = DAYS_1.days_code AND FARE_0.fare_basis_code = fare_basis.fare_basis_code AND NOT FARE_0.round_trip_cost IS NULL AND FLIGHT_FARE_0.fare_id = FARE_0.fare_id AND flight.flight_days = DAYS_0.days_code AND flight.flight_id = FLIGHT_FARE_0.flight_id)) AND NOT FARE_1.round_trip_cost IS NULL AND FLIGHT_FARE_1.fare_id = FARE_1.fare_id AND flight.flight_id = FLIGHT_FARE_1.flight_id) AND CITY_1.city_code = AIRPORT_SERVICE_1.city_code AND CITY_1.city_name = 'ORLANDO' AND flight.to_airport = AIRPORT_SERVICE_1.airport_code) AND CITY_0.city_code = AIRPORT_SERVICE_0.city_code AND CITY_0.city_name = 'INDIANAPOLIS' AND flight.from_airport = AIRPORT_SERVICE_0.airport_code