Problem:
Score : 200 points

Problem Statement

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.

Constraints

S is a string consisting of lowercase English letters.

The length of S is between 1 and 100 (inclusive).

Input

Input is given from Standard Input in the following format:

S

Output

Print the minimum number of hugs needed to make S palindromic.

Sample Input 1

redcoder

Sample Output 1

1

For example, we can change the fourth character to o and get a palindrome redooder.

Sample Input 2

vvvvvv

Sample Output 2

0

We might need no hugs at all.

Sample Input 3

abcdabc

Sample Output 3

2

Solution in C (GCC 5.4.1) (judge verdict: Wrong Answer)

#include<stdio.h>
#include<string.h>
int main()
{
	char str1[1000],str2[1000];
	int len1,count;
	scanf("%s",str1);
	len1=strlen(str1);
	printf("%d\n",len1);
	for(int i=0;i<len1;i++)
	{
		str2[i]=str1[len1-i-1];
	}
	printf("%s\n",str2);
	count=0;
	for(int i=0;i<len1;i++)
	{
		if(str1[i]!=str2[i])
			count++;
	}
	printf("%d\n",(count/2));
	return 0;
}