using System;

class Program
{
    static void Main()
    {
        string s = Console.ReadLine();

        int ans = 1;

        for (int i = 2; i < s.Length; i++)
        {
            for (int j = 0; j <= s.Length - i; j++)
            {
                for (int h = j; h <= j + (i - 1) / 2; h++)
                {
                    if (s[h] != s[2 * j + i - 1 - h]) break;
                    else if (h == j + (i - 1) / 2) ans = i;
                }
            }
        }

        Console.WriteLine(ans);
    }
}