static int sumOfBiggerThan(TreeNode node, int n) {        
            
            if (node == null) 
                return 0;
                        
            if (node.item > n)
                return node.item + sumOfBiggerThan(node.left, n) + sumOfBiggerThan(node.right, n);

            return sumOfBiggerThan(node.left, n) + sumOfBiggerThan(node.right, n);            
            
        }