which river flows through the cities of smolensk and kiev and empties into black sea?
return river ;return smolensk ;return kiev ;return #1 that flows through #2 ;return #1 that flows through #3 ;return #1 in  both  #4 and #5 ;return the  black sea ;return #6 that empties into #7
['select', 'select', 'select', 'filter', 'filter', 'intersection', 'select', 'filter']