Per recently learned about palindromes. Now he
wants to tell us about it and also has more awesome scientific
news to share with us.
“A palindrome is a word that is the same no matter whether
you read it backward or forward”, Per recently said in an
interview. He continued: “For example, add is not a
palindrome, because reading it backwards gives dda and
it’s actually not the same thing, you see. However, if we
reorder the letters of the word, we can actually get a
palindrome. Hence, we say that add is a
Peragram, because it is an anagram of a
palindrome”.
Per gives us a more formal definition of Peragrams:
“Like I said, if a word is an anagram of at least one
palindrome, we call it a Peragram. And recall that an
anagram of a word $w$
contains exactly the same letters as $w$, possibly in a different
order.”
Task
Given a string, find the minimum number of letters you have
to remove from it, so that the string becomes a Peragram.
Input
Input consists of a string on a single line. The string will
contain at least $1$ and
at most $1\, 000$
characters. The string will only contain lowercase letters
az.
Output
Output should consist of a single integer on a single line,
the minimum number of characters that have to be removed from
the string to make it a Peragram.
Sample Input 1 
Sample Output 1 
abc

2

Sample Input 2 
Sample Output 2 
aab

0
