Score : 200 points
Takahashi loves palindromes. Non-palindromic strings are unacceptable to him. Each time he hugs a string, he can change one of its characters to any character of his choice.
Given is a string S. Find the minimum number of hugs needed to make S palindromic.
Input is given from Standard Input in the following format:
S
Print the minimum number of hugs needed to make S palindromic.
redcoder
1
For example, we can change the fourth character to o
and get a palindrome redooder
.
vvvvvv
0
We might need no hugs at all.
abcdabc
2