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\n\nclass BIT:\n    def __init__(self,n):\n        self.tree = [0]*(n+1)\n        self.size = n\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)\ncount = Counter(S)\nflag = False\nfor v in list(count.values()):\n    if v%2 == 1:\n        if flag:\n            print((-1))\n            return\n        else:\n            flag = True\n\n\n"""\n文字sのi文字目がどこにあるか、をO(1)で取り出せる辞書が必要\n"""\nplaceAtS = {s:[] for s in list(set(S))}\nfor i in range(N):\n    s = S[i]\n    placeAtS[s].append(i)\n\ncount2 = {s:0 for s in list(set(S))}\n\nplaceAtT = [None]*(N)\ntmp = 0\nfor i in range(N):\n    s = S[i]\n    count2[s] += 1\n    if count2[s] <= count[s]//2:\n        placeAtT[i] = tmp\n        mirror = placeAtS[s][count[s]-count2[s]]\n        placeAtT[mirror] = N - tmp - 1\n        tmp += 1\n\nfor i in range(N):\n    if placeAtT[i] == None:\n        placeAtT[i] = tmp\n\nbit = BIT(N)\nans = 0\nfor i in range(N):\n    bit.add(placeAtT[i]+1,1)\n    ans += bit.sum(N) - bit.sum(placeAtT[i]+1)\n\nprint(ans)\n'
_co = compile(_CODE, USER_FILENAME, "exec")
exec(_co, ns, ns)

```

Measured memory_bytes: