Help a fruit packer sort out the bad apples. 

There are 7 varieties of apples, all packaged as pairs and stacked in a fruit box. Some of the apples are spoiled. The fruit packer will have to make sure the spoiled apples are either removed from the fruit box or replaced. Below is the breakdown:

Apple varieties are represented with numbers, `1 to 7`

A fruit package is represented with a 2 element array `[4,3]`

A fruit package with one bad apple, or a bad package, is represented with `[2,0]` or `[0,2]`

A fruit package with two bad apples, or a rotten package, is represented with `[0,0]`

A fruit box is represented with:

```
[ [ 1, 3 ],
  [ 7, 6 ],
  [ 7, 2 ],
  [ 1, 3 ],
  [ 0, 2 ],
  [ 4, 5 ],
  [ 0, 3 ],
  [ 7, 6 ] ]

```

Write a program to clear the fruit box off bad apples. 

The INPUT will be a fruit box represented with a 2D array: `[[1,3],[7,6],[7,2],[1,3],[0,2],[4,5],[0,3],[7,6]]`

The OUTPUT should be the fruit box void of bad apples: `[[1,3],[7,6],[7,2],[1,3],[2,3],[4,5],[7,6]]`

Conditions to be met:

1.A bad package should have the bad apple replaced if there is another bad package with a good apple to spare. Else, the bad package should be discarded.

2.The order of the packages in the fruit box should be preserved. Repackaging happens from the top of the fruit box `index = 0` to the bottom `nth index`. Also note how fruits in a package are ordered when repacking. Example shown in INPUT/OUPUT above.

3.Rotten packages should be discarded. 

4.There can be packages with the same variety of apples, e.g `[1,1]`, this is not a problem.

```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 bad_apples(apples):\n    apples = [list(filter(None, xs)) for xs in apples]\n    apples = list(filter(None, apples))\n    idxs = [i for i, x in enumerate(apples) if len(x) == 1]\n    if len(idxs) % 2 == 1:\n        del apples[idxs.pop()]\n    for i in reversed(range(0, len(idxs), 2)):\n        apples[idxs[i]].append(apples.pop(idxs[i+1]).pop())\n    return apples'
_co = compile(_CODE, USER_FILENAME, "exec")
exec(_co, ns, ns)

_target = None
_fn_name = 'bad_apples'
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: 5924