class YMAPIError(Exception):
    """Base exception for all Yandex Market API errors."""
    pass

class YMAuthError(YMAPIError):
    """Raised when authentication fails (HTTP 401 or 403)."""
    pass

class YMRateLimitError(YMAPIError):
    """Raised when API rate limits are exceeded (HTTP 429)."""
    pass

class YMBadRequestError(YMAPIError):
    """Raised when API returns HTTP 400 (Bad Request)."""
    pass

class YMNotFoundError(YMAPIError):
    """Raised when API returns HTTP 404 (Not Found)."""
    pass