import java.io.InputStream;
import java.io.PrintWriter;
import java.lang.reflect.Array;
import java.math.BigDecimal;
import java.math.MathContext;
import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.PriorityQueue;
import java.util.Queue;
import java.util.Scanner;
import java.util.Set;
import java.util.Stack;
import java.util.TreeMap;
import java.util.TreeSet;

import static java.util.Comparator.*;

public class Main {
    public static void main(String[] args) {
        PrintWriter out = new PrintWriter(System.out);
        Solver solver = new Solver(System.in, out);
        solver.solve();
        out.close();
    }
}
class Solver {
	Scanner sc;
	PrintWriter out;
    public Solver(InputStream in, PrintWriter out) {
    	sc = new Scanner(in);
    	this.out = out;
    }
    // ==================================================================
    public void solve() {
    	char[] C = sc.next().toCharArray();
    	int ans = 0, cnt, offset;
    	for (int i = 1; i < C.length; i++) {
    		cnt = 0;
    		offset = 1;
			while((i - offset) >= 0 && (i + offset - 1) <= (C.length - 1)) {
//				out.println(" i = " + i + "  offset = " + offset
//						+ "  C[" + (i - offset) + "] = " + C[i - offset]
//						+ "  C[" + (i + offset - 1) + "] = " + C[i + offset - 1]);
				if(C[i - offset] == C[i + offset - 1]) 	cnt += 2;
				offset++;
			}
			ans = Math.max(ans, cnt);
		}
    	for (int i = 1; i < C.length; i++) {
    		cnt = 1;
    		offset = 1;
			while((i - offset) >= 0 && (i + offset) <= (C.length - 1)) {
//				out.println(" i = " + i + "  offset = " + offset
//						+ "  C[" + (i - offset) + "] = " + C[i - offset]
//						+ "  C[" + (i + offset) + "] = " + C[i + offset]);
				if(C[i - offset] == C[i + offset]) 	cnt += 2;
				offset++;
			}
			ans = Math.max(ans, cnt);
		}
    	out.println(ans == 0 ? 1 : ans);
    }
}