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 Java8 (OpenJDK 1.8.0) (judge verdict: Runtime Error)

import java.util.*;

public class Main{
  public static void main(String[]args){
    Scanner sc=new Scanner(System.in);
    String SS=sc.nextLine();
    String[]sr=SS.split("");
    int count =0;
    int K=SS.length();
    if(K!=1){
      for(int i=0;i<K/2;i++){
        if(sr[i]==sr[K-i]){
          count+=0;
        }else if(sr[i]!=sr[K-i]){
          count+=1;
          sr[i]=sr[K-i];
        }
      }
    }
          if(K==1){
      System.out.println("0");
    }
    if(count!=0){
      System.out.println("count");
    }

    }
  }