what is the capitol of the country whose northern border is poland and germany?
return countries ;return poland ;return germany ;return northern borders of #1 ;return #1 where  #4 is #2 ;return #1 where  #4 is #3 ;return #1 in  both  #5 and #6 ;return capitol of #7
['select', 'select', 'select', 'project', 'comparative', 'comparative', 'intersection', 'project']