You are given a string S consisting of lowercase English letters.
Determine whether we can turn S into a palindrome by repeating the operation of swapping two adjacent characters. If it is possible, find the minimum required number of operations.

-----Constraints-----
 - 1 \leq |S| \leq 2 × 10^5
 - S consists of lowercase English letters.

-----Input-----
Input is given from Standard Input in the following format:
S

-----Output-----
If we cannot turn S into a palindrome, print -1. Otherwise, print the minimum required number of operations.

-----Sample Input-----
eel

-----Sample Output-----
1

We can turn S into a palindrome by the following operation:
 - Swap the 2-nd and 3-rd characters. S is now ele.

```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

ns = {"__name__": "__main__"}
for _k, _v in list(globals().items()):
    if not _k.startswith("_"):
        ns[_k] = _v
_CODE = "#!/usr/bin/env python3\n\nclass Bit:\n    def __init__(self, n):\n        self.size = n\n        self.tree = [0] * n\n\n    def sum(self, i):\n        s = 0\n        i -= 1\n        while i >= 0:\n            s += self.tree[i]\n            i = (i & (i + 1)) - 1\n        return s\n\n    def add(self, i, x):\n        while i < self.size:\n            self.tree[i] += x\n            i |= i + 1\n\na = ord('a')\n\ndef make_index(s):\n\n    index = [[] for _ in range(26)]\n    for i, ch in enumerate(s):\n        index[ord(ch) - a].append(i)\n\n    return index\n\ndef solve(s):\n\n    n = len(s)\n    index = make_index(s)\n\n    odd = None\n    for code, char_pos in enumerate(index):\n        if len(char_pos) % 2 == 1:\n            if odd is not None:\n                return -1\n            odd = code\n\n    bit = Bit(n)\n\n    ans = 0\n    cnt = 0\n    for i in range(n):\n        if bit.sum(i + 1) - bit.sum(i) == 1:\n            continue\n        code = ord(s[i]) - a\n        if code == odd and index[code][-1] == i:\n            continue\n        cnt += 1\n        j = index[code].pop()\n        ans += n - cnt - (j - bit.sum(j))\n        bit.add(j, 1)\n        if n // 2 <= cnt:\n            break\n\n    if odd is not None:\n        j = index[odd][-1]\n        ans += abs(n // 2 - (j - bit.sum(j)))\n\n    return ans\n\n\ndef main():\n    s = input()\n\n    print((solve(s)))\n\n\ndef __starting_point():\n    main()\n\n\n__starting_point()"
_co = compile(_CODE, USER_FILENAME, "exec")
exec(_co, ns, ns)

```

Measured memory_bytes: 17023