package com.company;

import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.*;

public class Main
{
    static List<Character> lol = Arrays.asList('a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v', 'w', 'x', 'y', 'z');


    public static void main(String[] args)
    {
        // write your code here
        Scanner sc = new Scanner(System.in);

        String word = sc.nextLine();

        // выделить подслова.
        if (isPolindrome(new StringBuilder(word)))
            System.out.println(0);
        else
        {
            Set<String> subwords = cutSubwordsFrom(word);

            int min = Integer.MAX_VALUE;

            for (String subword : subwords)
            {
                if (isAlmostPoli(subword))
                    if (min > (word.length() - subword.length()))

                        min = word.length() - subword.length();
            }

            System.out.println(min);
        }
    }

    private static boolean isPolindrome(StringBuilder word)
    {
        String start = word.toString();
        String reversed = word.reverse().toString();

        return reversed.equals(start);
    }

    private static Set<String> cutSubwordsFrom(String word)
    {
        StringBuilder builder = new StringBuilder(word);

        Set<String> subwords = new HashSet<>();

        for (int i = 0; i < word.length(); i++)
        {
            for (int j = i+1; j <= word.length(); j++)
            {
                char[] sub = new char[j - i];
                builder.getChars(i, j, sub, 0);
                subwords.add(new String(sub));
            }
        }

        return subwords;
    }

    private static boolean isAlmostPoli(String word)
    {

        for (int i = 0; i < word.length(); i++)
        {
            StringBuilder builder = new StringBuilder(word);
            builder = builder.deleteCharAt(i);

            if (isPolindrome(builder))
                return true;
        }

        for (Character lel : lol)
        {
            for (int i = 0; i < word.length(); i++)
            {
                StringBuilder builder = new StringBuilder(word);
                builder.setCharAt(i, lel);

                if (isPolindrome(builder))
                    return true;
            }

        }

        return false;
    }
}