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 = 'from string import ascii_lowercase\n\n\nclass Bit:\n    def __init__(self, n):\n        self.size = n\n        self.tree = [0] * (n + 1)\n\n    def sum(self, i):\n        s = 0\n        while i > 0:\n            s += self.tree[i]\n            i -= i & -i\n        return s\n\n    def add(self, i, x):\n        while i <= self.size:\n            self.tree[i] += x\n            i += i & -i\n\n\ndef solve(s):\n    indices = {c: [] for c in ascii_lowercase}\n    for i, c in enumerate(s):\n        indices[c].append(i)\n\n    n = len(s)\n    center = n // 2\n    bubbles = [-1] * n\n    odd_flag = False\n    lefts, rights = [], []\n    for c, ids in list(indices.items()):\n        cnt = len(ids)\n        if cnt & 1:\n            if odd_flag:\n                return -1\n            odd_flag = True\n            bubbles[ids[cnt // 2]] = center + 1\n        for i in range(cnt // 2):\n            li, ri = ids[i], ids[-i - 1]\n            if li < center:\n                lefts.append((li, ri))\n            else:\n                rights.append((li, ri))\n    lefts.sort()\n    rights.sort()\n    r_itr = iter(rights)\n    for i, (li, ri) in enumerate(lefts):\n        bubbles[li] = i + 1\n        bubbles[ri] = n - i\n    for i in range(len(lefts), center):\n        li, ri = next(r_itr)\n        bubbles[li] = i + 1\n        bubbles[ri] = n - i\n\n    ans = 0\n    bit = Bit(n)\n    for i, m in enumerate(bubbles):\n        ans += i - bit.sum(m)\n        bit.add(m, 1)\n    return ans\n\n\nprint((solve(input())))\n'
_co = compile(_CODE, USER_FILENAME, "exec")
exec(_co, ns, ns)

```

Measured memory_bytes: 16131