Given a string of characters, I want the function `findMiddle()`/`find_middle()` to return the middle number in the product of each digit in the string.

Example: 's7d8jd9' -> 7, 8, 9 -> 7\*8\*9=504, thus 0 should be returned as an integer.

Not all strings will contain digits. In this case and the case for any non-strings, return -1.

If the product has an even number of digits, return the middle two digits

Example: 1563 -> 56

NOTE: Remove leading zeros if product is even and the first digit of the two is a zero.
Example 2016 -> 1

```python

USER_FILENAME = "<user_code>"
import sys, json, builtins
import math, heapq, bisect, itertools, functools, collections, statistics, fractions, decimal, operator, array, random, re, string, os, pathlib
try:
    import resource as _res
except Exception:
    _res = None
from collections import Counter, defaultdict, deque, OrderedDict
from functools import lru_cache, reduce
from itertools import accumulate, permutations, combinations, product
from math import gcd, ceil, floor, sqrt
from decimal import Decimal
try:
    from typing import *
except Exception:
    pass
try:
    sys.setrecursionlimit(1_000_000)
except Exception:
    pass
try:
    import site as _site
    try:
        _sys_sites = _site.getsitepackages() if hasattr(_site, "getsitepackages") else []
        for _p in _sys_sites:
            if _p and _p not in sys.path:
                sys.path.append(_p)
    except Exception:
        pass
    try:
        _usp = _site.getusersitepackages()
        if isinstance(_usp, str):
            _usp = [_usp]
        for _p in _usp:
            if _p and _p not in sys.path:
                sys.path.append(_p)
    except Exception:
        pass
except Exception:
    pass

def _disabled_input(*args, **kwargs):
    raise RuntimeError("input() is disabled in callable mode")
builtins.input = _disabled_input

ns = {"__name__": "__judge__"}  # prevent if __name__ == "__main__" blocks
for _k, _v in list(globals().items()):
    if not _k.startswith("_"):
        ns[_k] = _v
_CODE = 'def find_middle(string):\n    # Если в String подаётся None, возвращаем -1\n    if string is None:\n        return -1\n    # Если в String подаётся число, возвращаем -1  \n    if type(string) is int:\n        return -1\n\n    # Если в String передаётся массив, возвращаем -1\n    if type(string) is list:\n        return -1\n\n    # Создаём массив и вносим туда только числа из String\n    spisok = []\n    for i in string:\n        if i.isdigit():\n            spisok.append(i)\n\n    # Если в String не было чисел, значит возвращаем -1\n    if len(spisok) == 0:\n        return -1\n\n    # Создаём переменную, в которой будет хранится число после перемножения всех чисел\n    spisok_ans = 1\n\n    # Перемножаем все числа\n    for i in spisok:\n        spisok_ans *= int(i)\n\n    # Переводим итоговое число в текст, для соблюдения условия задачи\n    spisok = str(spisok_ans)\n\n    # Если спи\n    if len(spisok) % 2 == 0:\n        if len(spisok) >= 2:\n            spisok[:1].replace("0", "")\n        test = int(len(spisok) / 2)\n        answer = spisok[test-1:test+1]\n    else:\n        test = int(len(spisok) / 2)\n        answer = spisok[test:test+1]\n\n    answer = "".join(answer)\n    return int(answer)'
_co = compile(_CODE, USER_FILENAME, "exec")
exec(_co, ns, ns)

_target = None
_fn_name = 'find_middle'
if _fn_name:
    if "Solution" in ns:
        try:
            _obj = ns["Solution"]()
            if hasattr(_obj, _fn_name):
                _target = getattr(_obj, _fn_name)
        except Exception:
            _target = None
    if _target is None and _fn_name in ns and callable(ns[_fn_name]):
        _target = ns[_fn_name]
# Fallback: if there's exactly one user-defined function, use it
if _target is None:
    _cands = [v for k, v in ns.items() if callable(v) and getattr(v, "__module__", "") in ("__judge__", "__main__")]
    _user_funcs = [c for c in _cands if getattr(c, "__name__", "").startswith("_") is False]
    if len(_user_funcs) == 1:
        _target = _user_funcs[0]
if _target is None:
    raise RuntimeError(f"Could not resolve callable '{_fn_name}'")

_raw = sys.stdin.read().strip()
if _raw:
    _parsed = json.loads(_raw)
    if isinstance(_parsed, dict):
        _kwargs = _parsed.get("kwargs", {})
        _args = _parsed.get("args", [])
    else:
        _args, _kwargs = _parsed, {}
else:
    _args, _kwargs = [], {}
if not isinstance(_args, (list, tuple)):
    _args = [_args]
_res = _target(*_args, **_kwargs)
try:
    sys.stdout.write(repr(_res) + "\n")
except Exception:
    pass

```

Measured memory_bytes: 6006