def find_object_with_key(obj, key_to_find):
    """
    Iteratively searches through a dictionary (JSON object) and returns the value for the specified key.
    :param obj: The JSON object (dictionary) to search through.
    :param key_to_find: The key to search for.
    :return: The object containing the key, or None if the key is not found.
    """
    stack = [obj]

    while stack:
        current = stack.pop()

        if isinstance(current, dict):
            if key_to_find in current:
                return current[key_to_find]

            for key in current:
                stack.append(current[key])

    return None


def find_path_to_key(obj, key_to_find):
    """
    Iteratively searches through a dictionary (JSON object) and returns the path to the specified key.
    :param obj: The JSON object (dictionary) to search through.
    :param key_to_find: The key to search for.
    :return: The path to the key, or None if the key is not found.
    """
    stack = [{'current': obj, 'path': ''}]

    while stack:
        current_item = stack.pop()
        current, path = current_item['current'], current_item['path']

        if isinstance(current, dict):
            if key_to_find in current:
                return f"{path}.{key_to_find}" if path else key_to_find

            for key in current:
                new_path = f"{path}.{key}" if path else key
                stack.append({'current': current[key], 'path': new_path})

    return None