from typing import Dict, Any
import json
import re


def extract_parse_json(input_str: str) -> Dict[str, Any]:
    """
    Extracts and parses a JSON object from the input string using regex if it is tagged with 'json\n'
    and enclosed in backticks, otherwise returns the input string.

    :param input_str: A string that may contain a JSON object.
    :return: A dictionary if JSON is parsed, otherwise the original string.
    """
    # Regex to match 'json\n{...}' pattern enclosed in backticks
    match = re.search(r"```json\n([\s\S]+?)\n```", input_str)
    if match:
        json_str = match.group(1)  # Extract the JSON string
        try:
            return json.loads(json_str)
        except json.JSONDecodeError:
            raise
    else:
        return json.loads(input_str)
