class Node:
    def __init__(self, val):
        self.val = val
        self.left = None
        self.right = None

def search(node, val):
    if not node:
        return False       # not found
    if val == node.val:
        return True        # found!
    elif val < node.val:
        return search(node.left, val)
    else:
        return search(node.right, val)

def insert(node, val):
    if not node:
        return Node(val)
    if val < node.val:
        node.left = insert(node.left, val)
    elif val > node.val:
        node.right = insert(node.right, val)
    return node