Given an array nums of integers, we need to find the maximum possible sum of elements of the array such that it is divisible by three.


 
Example 1:
Input: nums = [3,6,5,1,8]
Output: 18
Explanation: Pick numbers 3, 6, 1 and 8 their sum is 18 (maximum sum divisible by 3).
Example 2:
Input: nums = [4]
Output: 0
Explanation: Since 4 is not divisible by 3, do not pick any number.

Example 3:
Input: nums = [1,2,3,4,4]
Output: 12
Explanation: Pick numbers 1, 3, 4 and 4 their sum is 12 (maximum sum divisible by 3).

 
Constraints:

1 <= nums.length <= 4 * 10^4
1 <= nums[i] <= 10^4

```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 heapq\nfrom collections import defaultdict, Counter\nclass Solution:\n    '''Return the smallest / 2nd smallest element'''\n    def get_min_1_2(self, nums):\n        return heapq.nsmallest(2, nums)\n    \n    def maxSumDivThree(self, nums: List[int]) -> int:\n        sum_ = sum(nums)\n        mod_dic = defaultdict(list)    # Hash table: 1->[1, 7, 10...]\n        for num in nums:\n            mod_dic[num%3].append(num)\n        print(mod_dic)\n            \n        if sum_%3 == 0:\n            return sum_\n        \n        if sum_%3 == 1:\n            sum1 = -float('inf')\n            sum2 = -float('inf')\n            if 1 in mod_dic:\n                sum1 = sum_ - min(mod_dic[1])\n            if 2 in mod_dic and len(mod_dic[2]) >= 2:\n                min_mod2, second_min_mod2 = self.get_min_1_2(mod_dic[2])\n                # min_mod2 = min(mod_dic[2])\n                # mod_dic[2].remove(min_mod2)\n                # second_min_mod2 = min(mod_dic[2])\n                sum2 = sum_ - min_mod2 - second_min_mod2\n            return max(sum1, sum2)\n        \n        if sum_%3 == 2:\n            sum1 = -float('inf')\n            sum2 = -float('inf')\n            if 2 in mod_dic:\n                sum2 = sum_ - min(mod_dic[2])\n            if 1 in mod_dic and len(mod_dic[1]) >= 2:\n                min_mod1, second_min_mod1 = self.get_min_1_2(mod_dic[1])\n                # min_mod1 = min(mod_dic[1])\n                # mod_dic[1].remove(min_mod1)\n                # second_min_mod1 = min(mod_dic[1])\n                sum1 = sum_ - min_mod1 - second_min_mod1\n            return max(sum1, sum2)\n"
_co = compile(_CODE, USER_FILENAME, "exec")
exec(_co, ns, ns)

_target = None
_fn_name = 'maxSumDivThree'
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: 6758