public static Node insert(Node root,int data) {
        Node newNode = new Node(data);
        
        if (root == null) {
            return newNode;
        }
        
        Node current = root;
    	root = current;
        
        while (true) {
            if (data > current.data) {
                if (current.right == null) {
                    current.right = newNode;
                    return root;
                } else {
                    current = current.right;
                }
            } else if (data < current.data) {
                if (current.left == null) {
                    current.left = newNode;
                    return root;
                } else {
                    current = current.left;
                }
            }
        }
    }