### ** papplesort**

### papplesort

### Problem Statement

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 ≤ |S| ≤ 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 1

eel

### Sample Output 1

1

We can turn `S` into a palindrome by the following operation:

- Swap the
`2`-nd and `3`-rd characters. `S` is now `ele`

.

### Sample Input 2

ataatmma

### Sample Output 2

4

We can turn `S` into a palindrome by the following operation:

- Swap the
`5`-th and `6`-th characters. `S` is now `ataamtma`

.
- Swap the
`4`-th and `5`-th characters. `S` is now `atamatma`

.
- Swap the
`3`-rd and `4`-th characters. `S` is now `atmaatma`

.
- Swap the
`2`-nd and `3`-rd characters. `S` is now `amtaatma`

.

### Sample Input 3

snuke

### Sample Output 3

-1

We cannot turn `S` into a palindrome.