## Task

Given a string, add the fewest number of characters possible from the front or back to make it a palindrome.

## Example

For the input `cdcab`, the output should be `bacdcab`

## Input/Output

Input is a string consisting of lowercase latin letters with length 3 <= str.length <= 10

The output is a palindrome string satisfying the task.

For s = `ab` either solution (`aba` or `bab`) will be accepted.

```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 is_palindrome(s):\n    """Check if s is a palindrome"""\n    return s == s[::-1]\n\n\ndef left_strip_palindrome(s):\n    """Keeps stripping from left to find a palindrome. If not found return None. \n    If found return the stripped characters in stripping order"""\n    for i in range(len(s)-1):\n        if is_palindrome(s[i:]):\n            return s[:i]\n    return None\n\ndef right_strip_palindrome(s):\n    """Keeps stripping from right to find a palindrome. If not found return None. \n    If found return the stripped characters in stripping order"""\n    for i in range(-1,1-len(s),-1):\n        if is_palindrome(s[:i]):\n            return s[i:]\n            \ndef build_palindrome(s):\n    """Build a palindrome by adding the min number of characters possible."""\n    lsp = left_strip_palindrome(s)\n    rsp = right_strip_palindrome(s)\n    # Answer is obtained by getting the stripped characters and add them in reverse order \n    # to the opps direction they were stripped from in reverse direction.\n    if lsp is not None:\n        lsp_ans = s+lsp[::-1]\n        if rsp is not None:\n            rsp_ans = rsp[::-1]+s\n            # In the case both left stripping and right stripping works, return the shortest answer.\n            return min((lsp_ans,rsp_ans), key=len)\n        return lsp_ans\n            \n    if rsp is not None:\n        rsp_ans = rsp[::-1]+s\n        return rsp_ans\n    \n    # If stripping does not work return the string with the copy of all characters \n    # but the first concatenated at the starting in reverse order.\n    return s[1:][::-1]+s\n'
_co = compile(_CODE, USER_FILENAME, "exec")
exec(_co, ns, ns)

_target = None
_fn_name = 'build_palindrome'
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: 5898