Which group from the census in Skopje is smaller: Macedonians or Serbs?
return Skopje ;return the  census of #1 ;return Macedonians of #2 ;return Serbs of #2 ;return number of  #3 ;return number of  #4 ;return which is the  lowest of #5 ,  #6
['select', 'project', 'project', 'project', 'aggregate', 'aggregate', 'comparison']