import java.io.*;
import java.util.*;
import java.util.function.*;
import java.util.stream.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        char[] inputs = sc.next().toCharArray();
        int ans = 1;
        for (int i = 0; i < inputs.length; i++) {
            for (int j = i + ans; j < inputs.length; j++) {
                if (i == 0 && j == inputs.length - 1) {
                    continue;
                }
                boolean enable = true;
                int left = i;
                int right = j;
                while (enable && left < right) {
                    enable = (inputs[left] == inputs[right]);
                    left++;
                    right--;
                }
                if (enable) {
                    ans = Math.max(ans, j - i + 1);
                }
            }
        }
        System.out.println(ans);
    }
}
class Scanner {
    BufferedReader br;
    StringTokenizer st = new StringTokenizer("");
    StringBuilder sb = new StringBuilder();
    
    public Scanner() {
        try {
            br = new BufferedReader(new InputStreamReader(System.in));
        } catch (Exception e) {
            
        }
    }
    
    public int nextInt() {
        return Integer.parseInt(next());
    }
    
    public long nextLong() {
        return Long.parseLong(next());
    }
    
    public double nextDouble() {
        return Double.parseDouble(next());
    }
    
    public String next() {
        try {
            while (!st.hasMoreTokens()) {
                st = new StringTokenizer(br.readLine());
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            return st.nextToken();
        }
    }
    
}