import java.io.*;
import java.util.*;

class Main {
	
	public static void out (Object o) {
		System.out.println(o);
	}
	
	public static boolean isReversible (String s) {
		int len = s.length();
		for (int i = 0; i < len / 2; i++) {
			if (s.charAt(i) != s.charAt(len - i - 1)) return false;
		}
		return true;
	}
	
	public static int solve (String s) {
		int len = s.length();
		for (int i = len - 1; i > 0; i--) {
			for (int j = 0; i + j <= len; j++) {
				String sub = s.substring(j , i + j);
				//out(sub);
				if (isReversible(sub)) return i;
			}
		}
		return 0;
	}
	
	public static void main (String[] args) throws IOException {
		BufferedReader br = 
			new BufferedReader(new InputStreamReader(System.in));
		
		out(solve(br.readLine()));
	}
}