How many screens do Landmark Theatres and Marcus Theatres have combined?
return Landmark Theatres ;return Marcus Theatres ;return screens of #1 ;return screens of #2 ;return number of  #3 ;return number of  #4 ;return the  sum of #5 and  #6
['select', 'select', 'project', 'project', 'aggregate', 'aggregate', 'arithmetic']