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 Java7 (OpenJDK 1.7.0) (judge verdict: Accepted)

import java.util.*;
public class Main {

   public static void main(String[] args) {
    int count=0;
    int temp=0;
  	Scanner scan=new Scanner(System.in); 
    String s=scan.next(); 
    char[] ch = new char[s.length()];
    char[] rev = new char[s.length()];
    for (int i = 0; i < ch.length; i++) { 
            ch[i] = s.charAt(i); 
    } 
    for (int i = rev.length-1; i >=0; i--) { 
            rev[temp] = s.charAt(i); 
      		temp++;
    } 
    for(int i = 0; i<= (ch.length/2)-1; i++) {
    	if(ch[i] != rev[i]){
        count++;
        }
    }
    System.out.println(count);
   }
}