There is a house with 4 levels.
In that house there is an elevator.
You can program this elevator to go up or down,
depending on what button the user touches inside the elevator.

Valid levels must be only these numbers: `0,1,2,3`

Valid buttons must be only these strings: `'0','1','2','3'` 

Possible return values are these numbers: `-3,-2,-1,0,1,2,3`

If the elevator is on the ground floor(0th level) 
and the user touches button '2'
the elevator must go 2 levels up,
so our function must return 2.

If the elevator is on the 3rd level
and the user touches button '0'
the elevator must go 3 levels down, so our function must return -3.

If the elevator is on the 2nd level,
and the user touches button '2'
the elevator must remain on the same level,
so we return 0.

We cannot endanger the lives of our passengers, 
so if we get erronous inputs, 
our elevator must remain on the same level.
So for example:

- `goto(2,'4')` must return 0, because there is no button '4' in the elevator.
- `goto(4,'0')` must return 0, because there is no level 4.
- `goto(3,undefined)` must return 0.
- `goto(undefined,'2')` must return 0.
- `goto([],'2')` must return 0 because the type of the input level is array instead of a number.
- `goto(3,{})` must return 0 because the type of the input button is object instead of a string.

```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 = "levels = [0, 1, 2, 3]\nbuttons = ['0', '1', '2', '3']\ndef goto(level,button):\n    if level not in levels or button not in buttons:\n        return 0\n    else:\n        return int(button) - level"
_co = compile(_CODE, USER_FILENAME, "exec")
exec(_co, ns, ns)

_target = None
_fn_name = 'goto'
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: 5338