GPT-5.3-Codex vs GPT-5.6 Solfor coding

```python
import re

def parse_duration(s: str) -> int:
    """
    Convert duration strings like:
      '1h30m', '45s', '2h', '90m', '1h2m3s'
    into total seconds.

    Rules:
    - Units must be in h -> m -> s order if present.
    - Each unit can appear at most once.
    - At least one unit must be present.
    - No extra characters/spaces allowed.
    """
    if not isinstance(s, str):
        raise ValueError("Duration must be a string")

    m = re.fullmatch(r'(?:(\d+)h)?(?:(\d+)m)?(?:(\d+)s)?', s)
    if not m:
        raise ValueError…

```python
import re

_DURATION_PATTERN = re.compile(
    r"(?:(?P<hours>[0-9]+)h)?"
    r"(?:(?P<minutes>[0-9]+)m)?"
    r"(?:(?P<seconds>[0-9]+)s)?"
)


def parse_duration(s):
    if not isinstance(s, str) or not s:
        raise ValueError("Malformed duration")

    match = _DURATION_PATTERN.fullmatch(s)
    if not match:
        raise ValueError(f"Malformed duration: {s!r}")

    hours = int(match.group("hours") or 0)
    minutes = int(match.group("minutes") or 0)
    seconds = int(match.group("seconds") or 0)

    return hours * 3600 + minu…