[BasE91](http://base91.sourceforge.net/) is a method for encoding binary as ASCII characters. It is more efficient than Base64 and needs 91 characters to represent the encoded data.

The following ASCII charakters are used:

    'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789'
    '!#$%&()*+,./:;<=>?@[]^_`{|}~"'
    
Create two functions that encode strings to basE91 string and decodes the other way round. 

    b91encode('test') = 'fPNKd'
    b91decode('fPNKd') = 'test'
    
    b91decode('>OwJh>Io0Tv!8PE') = 'Hello World!'
    b91encode('Hello World!') = '>OwJh>Io0Tv!8PE'
    
Input strings are valid.

```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 = 'import struct\n\nCHARSET = (\'ABCDEFGHIJKLMNOPQRSTUVWXYZ\'\n           \'abcdefghijklmnopqrstuvwxyz\'\n           \'0123456789!#$%&()*+,./:;<=>?@[]^_`{|}~"\')\n\ndef b91decode(message):\n    value = stack = 0\n    out = bytes()\n    for first, second in zip(message[::2], message[1::2]):\n        cipher = CHARSET.index(first) + CHARSET.index(second) * 91\n        value |= cipher << stack\n        stack += 13 + ((cipher & 8191) < 89)\n        while stack > 7:\n            out    += struct.pack(\'B\', value & 255)\n            value >>= 8\n            stack  -= 8\n    if len(message) % 2:\n        rogue = message[-1]\n        out  += struct.pack(\'B\', (value | CHARSET.index(rogue) << stack) & 255)\n    return out.decode(\'utf-8\')\n\ndef b91encode(data):\n    value = stack = 0\n    out = \'\'\n    for (byte,) in struct.iter_unpack(\'B\', bytes(data, \'utf-8\')):\n        value |= byte << stack\n        stack += 8\n        if stack > 13:\n            cipher = value & 8191\n            if cipher > 88:\n                value >>= 13\n                stack  -= 13\n            else:\n                cipher  = value & 16383\n                value >>= 14\n                stack  -= 14\n            out += CHARSET[cipher % 91] + CHARSET[cipher // 91]\n    return out + (value > 0) * CHARSET[value % 91]'
_co = compile(_CODE, USER_FILENAME, "exec")
exec(_co, ns, ns)

_target = None
_fn_name = 'b91decode'
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: 6327