Write Prolog rules as described in the questions below. You may use any Prolog builtin predicates.

A binary tree is defined by the structure node(left,right), where left and right can be either another node or any Prolog data item. Write the rule size(Tree,Size) that takes as input a tree and returns the number of leaf items in the tree. For example: ?- size(node(1,2),X). X = 2. ?- size(node(1,[2,3,4]),X). X = 2. ?- size(node(node(a,b),[2,3,4]),X). X = 3.