import java.util.*;
import java.io.*;
import java.math.*;
import java.util.stream.Stream;

public class Main{
    /* 入出力 */
    static BufferedReader buff = new BufferedReader(new InputStreamReader(System.in));
    static StringTokenizer st;
    static PrintWriter output = new PrintWriter(System.out);
    static Scanner sc = new Scanner(System.in);
    /* 定数 */
    static final int [] y4 = {0,1,0,-1};
    static final int [] x4 = {1,0,-1,0};
    static final int  INF1 = Integer.MAX_VALUE;
    static final long INF2 = Long.MAX_VALUE;
    static final long MOD1 = (long)1e9+7;
    static final long MOD2 = 998244353;
    /* Main */
    public static void main(String[] args) throws IOException{
        String S = sc.next();
        int max = -INF1;
        for(int i=S.length();i>=1;i--) { //i以上で分割
            StringBuilder sb = new StringBuilder();
            int len = 0;
            for(int s=0;s<S.length();s++) {
                sb.append(S.substring(s,s+1));
                if(i <= sb.length()) {
                    String base = sb.toString();
                    String reve = sb.reverse().toString();
                    sb.reverse();
                    if(base.equals(reve)) {
                        len += base.length();
                        sb.delete(0,sb.length());
                    }
                }
            }
            if(len == S.length()) {
                max = i;
                break;
            }
        }
        output.print(max);
        output.flush();        
    }
}