class BinaryTree:

    def __init__(self, root):
        self._root = root
        self._left_branch = None
        self._right_branch = None

    def insert(self, value):

        if self._root is None:
            self._root = value

        if value > self._root:
            if self._right_branch is None:
                self._right_branch = BinaryTree(value)
            else:
                self._right_branch.insert(value)
        else:
            if self._left_branch is None:
                self._left_branch = BinaryTree(value)
            else:
                self._left_branch.insert(value)



if __name__ == '__main__':
    bst1 = BinaryTree(7)
    bst1.insert(9)
    bst1.insert(4)