What are the themes of competitions that have corresponding host cities with more than 1000 residents?
return competitions ;return host cities of  #1 ;return residents of  #2 ;return number of  #3 for each  #2 ;return #1 where #4 is  higher than 1000 ;return themes of  #5
['select', 'project', 'project', 'group', 'comparative', 'project']