import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		String S = scan.next();
		scan.close();
		int l = S.length();
		char[]c1 = new char[l];
		char[]c2 = new char[l];
		for(int i = 0; i < l; i++) {
			c1[i] = S.charAt(i);
			c2[i] = S.charAt(l - i - 1);
		}
		int max = 0;
		for(int i = 0; i < l; i++) {
			int cnt = 0;
			for(int j = i; j < l; j++) {
				if(c1[j] == c2[j - i]) {
					cnt++;
				}
			}
			max = Math.max(max, cnt);
		}
		System.out.println(max);
	}
}