The town sheriff dislikes odd numbers and wants all odd numbered families out of town! In town crowds can form and individuals are often mixed with other people and families. However you can distinguish the family they belong to by the number on the shirts they wear. As the sheriff's assistant it's your job to find all the odd numbered families and remove them from the town!
~~~if-not:cpp
Challenge: You are given a list of numbers. The numbers each repeat a certain number of times. Remove all numbers that repeat an odd number of times while keeping everything else the same.
~~~
~~~if:cpp
Challenge: You are given a vector of numbers. The numbers each repeat a certain number of times. Remove all numbers that repeat an odd number of times while keeping everything else the same.
~~~
```python
odd_ones_out([1, 2, 3, 1, 3, 3]) = [1, 1]
```
In the above example:
- the number 1 appears twice
- the number 2 appears once
- the number 3 appears three times

`2` and `3` both appear an odd number of times, so they are removed from the list. The final result is: `[1,1]`

Here are more examples:
```python
odd_ones_out([1, 1, 2, 2, 3, 3, 3]) = [1, 1, 2, 2]
odd_ones_out([26, 23, 24, 17, 23, 24, 23, 26]) = [26, 24, 24, 26]
odd_ones_out([1, 2, 3]) = []
odd_ones_out([1]) = []
```

Are you up to the challenge?

```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 = 'from collections import Counter\n\ndef odd_ones_out(a):\n    d = Counter(a)\n    return [x for x in a if not d[x] % 2]'
_co = compile(_CODE, USER_FILENAME, "exec")
exec(_co, ns, ns)

_target = None
_fn_name = 'odd_ones_out'
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: 9500