i'm looking for a flight from boston to denver that has no stopovers and is only in the afternoon 
return flights ;return #1 from  boston ;return #1 to denver ;return #1 of  both #2 and  #3 ;return #4 with no stopovers ;return #5 in the  afternoon
['select', 'filter', 'filter', 'intersection', 'filter', 'filter']