list nonstop flights on sunday from new york to las vegas and list nonstop flights on sunday from memphis to las vegas 
return flights ;return #1 that  are nonstop  ;return #2 from  new york ;return #3 to las  vegas ;return #4 on  sunday ;return #2 from  memphis ;return #6 to las  vegas ;return #7 on  sunday ;return #5 , #8
['select', 'filter', 'filter', 'filter', 'filter', 'filter', 'filter', 'filter', 'union']