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 = "import sys\nclass BIT():\n    def __init__(self,number):\n        self.n=number\n        self.list=[0]*(number+1)\n        \n    def add(self,i,x):#ith added x  1indexed\n        while i<=self.n:\n            self.list[i]+=x\n            i+=i&-i\n            \n    def search(self,i):#1-i sum\n        s=0\n        while i>0:\n            s+=self.list[i]\n            i-=i&-i\n        return s\n    \n    def suma(self,i,j):#i,i+1,..j sum\n        return self.search(j)-self.search(i-1)\n#from collections import defaultdict\nS=input()\nN = len(S)\nL = 26\na = ord('a')\nd = [[] for i in range(L)]\nfor i in range(N):\n    s=ord(S[i])-a\n    d[s].append(i)\nflag=0\nfor i in range(L):\n    if len(d[i])%2==1:\n        flag+=1\nif flag>1:\n    print(-1)\n    return\nSuc=[-1]*N\npairs=[]\nfor i in range(L):\n    T=len(d[i])\n    for s in range((T//2)):\n        li,ri=d[i][s],d[i][-s-1]\n        pairs.append((li,ri))\n    if T%2==1:\n        Suc[d[i][T//2]]=(N//2)+1\npairs.sort()\nfor i, (li,ri) in enumerate(pairs):\n    Suc[li]=i+1\n    Suc[ri]=N-i\nTree=BIT(N+3)\nans=0\nfor i,m in enumerate(Suc):\n    ans+=i-Tree.search(m)\n    Tree.add(m,1)\n#ans+=Tree.search(N+1)\nprint(ans)"
_co = compile(_CODE, USER_FILENAME, "exec")
exec(_co, ns, ns)

```

Measured memory_bytes: