---

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




class Binary_Search_Tree:
   def __init__(self):
      self.root = None
      self.size = 0




      def append(self,val):
        new_node = None(val)
        if not self.root:
            self.root = new_node
            return
        cur = self.root
        while cur:
            if cur.val > val:
                if not cur.left:
                    cur.left = new_nod
                    return
                cur = cur.left
            else:
               if not cur.right:
                  cur.right = new_node