The Largest Bouquet

It's autumn now, the time of the leaf fall. Sergey likes to collect fallen leaves in autumn. In his city, he can find fallen leaves of maple, oak and poplar. These leaves can be of three different colors: green, yellow or red. Sergey has collected some leaves of each type and color. Now he wants to create the biggest nice bouquet from them. He considers the bouquet nice iff all the leaves in it