What primary color is present in color of the smallestt cube and not present as the main color of one of the other cubes?
return cubes ;return the   size of   cubes ;return #1 where #2 is  smallestt ;return the   primary color  of   #3 ;return #4 and not on any  other cubes
['select', 'select', 'superlative', 'project', 'filter']