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