How many objects are made of the same material as the small brown ball? 
return objects ;return small ball ;return #2 that  is  brown ;return material of #1 ;return material of #3 ;return #1 where #4 is  the  same as #5 ;return number of  #6
['select', 'select', 'filter', 'project', 'project', 'comparative', 'aggregate']