package no273;

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		char[] s = sc.next().toCharArray();
		int n = s.length;
		int ans = 0;
		for(int i=0;i<n;i++) {
			LOOP: for(int j=i;j<n;j++) {
				for(int k=i;k<=j;k++) {
					if (s[k] != s[j-(k-i)]) {
						continue LOOP;
					}
				}
				int len = j - i + 1;
				if (len < n) {
					ans = Math.max(ans,len);
				}
			}
		}
		System.out.println(ans);
	}

}