国王的魔镜

import java.util.Scanner;
public class Main{
    public static void main(String[] args){
       Scanner sc=new Scanner(System.in);
        String str;
        str=sc.nextLine();
        int len=str.length();
        StringBuilder sb=new StringBuilder(str.substring(len/2,len));
        while(str.substring(0,len/2).compareTo(String.valueOf(sb.reverse()))==0){
            len=len/2;
            sb=new StringBuilder(str.substring(len/2,len));
        }
        System.out.println(len);
    }
}