show me the flight with the smallest seating capacity which leaves pittsburgh and arrives in baltimore on june fourteenth 
return flights ;return #1 from  pittsburgh ;return #2 to baltimore ;return #3 on june fourteenth ;return seating capacities of #4 ;return #4 where #5 is the  lowest
['select', 'filter', 'filter', 'filter', 'project', 'comparative']