import java.util.Arrays;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.Scanner;

public class Main {
	
	public static long MOD = 1000000007;
	
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		
		final char[] input = sc.next().toCharArray();
		
		
		int answer = 0;
		for(int start = 0; start < input.length; start++){
			
			// for_odd
			
			int odd_count = 1;
			for(int diff = 1; diff <= input.length; diff++){
				final int left = start - diff;
				final int right = start + diff;
				
				if(left < 0 || right >= input.length){ break; }
				if(input[left] == input[right]){ odd_count += 2; }
			}
			
			int even_count = 0;
			for(int diff = 1; diff <= input.length; diff++){
				final int left = start - (diff - 1);
				final int right = start + diff;
				
				if(left == 0 || right >= input.length){ break; }
				if(input[left] == input[right]){ even_count += 2; }
			}
			
			answer = Math.max(answer, Math.max(odd_count, even_count));
		}
		
		System.out.println(answer);
	}
}