def bst_insert(root: dict | None, name: str, phone: str) -> dict:
    if root is None:
        return {'name': name, 'phone': phone, 'left': None, 'right': None}

    if name < root['name']:
        root['left'] = bst_insert(root['left'], name, phone)
    elif name > root['name']:
        root['right'] = bst_insert(root['right'], name, phone)
    else:
        root['phone'] = phone

    return root


def bst_find(root: dict | None, name: str) -> str | None:
    current = root

    while current is not None:
        if name == current['name']:
            return current['phone']
        elif name < current['name']:
            current = current['left']
        else:
            current = current['right']

    return None


def _min_value(node: dict) -> dict:
    while node['left'] is not None:
        node = node['left']
    return node


def bst_delete(root: dict | None, name: str) -> dict | None:
    if root is None:
        return None

    if name < root['name']:
        root['left'] = bst_delete(root['left'], name)

    elif name > root['name']:
        root['right'] = bst_delete(root['right'], name)

    else:

        if root['left'] is None:
            return root['right']
        if root['right'] is None:
            return root['left']
        successor = _min_value(root['right'])
        root['name'] = successor['name']
        root['phone'] = successor['phone']
        root['right'] = bst_delete(root['right'], successor['name'])

    return root


def bst_list_all(root: dict | None) -> list:
    result = []

    def walk(node: dict | None):
        if node is None:
            return
        walk(node['left'])
        result.append((node['name'], node['phone']))
        walk(node['right'])

    walk(root)
    return result