i'd like also to book a one way flight from pittsburgh to atlanta the cheapest one on july twentieth 
return flights ;return #1 that  are  one way ;return #2 from  pittsburgh ;return #3 to atlanta ;return #4 on  july twentieth ;return #5 that  is  cheapest
['select', 'filter', 'filter', 'filter', 'filter', 'filter']