import java.util.*;

public class Main {
	public static void main (String[] args) {
		Scanner sc = new Scanner(System.in);
		char[] arr = sc.next().toCharArray();
		int max = 1;
		for (int  i = 0; i < arr.length; i++) {
		    int count1 = 1;
		    for (int j = 1; i - j >= 0 && i + j < arr.length; j++) {
		        if (arr[i - j] == arr[i + j]) {
		            count1 += 2;
		        }
		    }
		    max = Math.max(max, count1);
		    int count2 = 0;
		    for (int j = 0; i - j >= 0 && i + j + 1 < arr.length; j++) {
		        if (arr[i - j] == arr[i + j + 1]) {
		            count2 += 2;
		        }
		    }
		    max = Math.max(max, count2);
		}
	    System.out.println(max);
	}
}