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 collections import Counter,defaultdict\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\ns = input()\nn = len(s)\nc = Counter(s)\nflg = 0\nif n%2 == 0:\n  for i in c.values():\n    if i%2:\n      print(-1)\n      return\nelse:\n  for st,i in c.items():\n    if i%2 and flg:\n      print(-1)\n      return\n    elif i%2:\n      flg = 1\nans = 0\nfstr = []\nlstr = []\ndc = defaultdict(int)\nptr = 0\nfor i in range(n):\n  si = s[i]\n  dc[si] += 1\n  cnt = dc[si]\n  if c[si]%2:\n    if cnt*2-1 == c[si]:\n      ans += i-ptr\n      continue\n  if cnt <= c[si]//2:\n    ans += i-ptr\n    ptr += 1\n    fstr.append(si)\n  else:\n    lstr.append(si)\nlstr = lstr[::-1]\nn //= 2\nperm = [0]*n\nfdc = defaultdict(list)\nldc = defaultdict(int)\nlcnt = 0\nfor i in range(n):\n  fi = fstr[i]\n  fdc[fi].append(i+1)\nfor i in range(n):\n  li = lstr[i]\n  perm[i] = fdc[li][ldc[li]]\n  ldc[li] += 1\nsol = Bit(n+2)\nfor i in range(n):\n  p = perm[i]\n  ans += sol.sum(n+1)-sol.sum(p)\n  sol.add(p,1)\nprint(ans)'
_co = compile(_CODE, USER_FILENAME, "exec")
exec(_co, ns, ns)

```

Measured memory_bytes: