using System; using System.IO; using System.Linq; using System.Text; using System.Collections.Generic; using System.Diagnostics; using Enu = System.Linq.Enumerable; public class Program { public void Solve() { var S = Reader.String(); int N = S.Length; int ans = 1; for (int center = 0; center < N; center++) for (int centerLen = 1; centerLen <= 2 && center + centerLen <= N; centerLen++) { int len = 1; if (centerLen == 2 && S[center] == S[centerLen]) len = 2; for (int L = center - 1, R = center + centerLen; L >= 0 && R < N; L--, R++) if (S[L] == S[R]) len += 2; ans = Math.Max(ans, len); } Console.WriteLine(ans); } } class Entry { static void Main() { new Program().Solve(); } } class Reader { static TextReader reader = Console.In; static readonly char[] separator = { ' ' }; static readonly StringSplitOptions op = StringSplitOptions.RemoveEmptyEntries; static string[] A = new string[0]; static int i; static void Init() { Dispose(); A = new string[0]; } public static void Set(TextReader r) { Init(); reader = r; } public static void Set(string file) { Init(); reader = new StreamReader(file); } public static bool HasNext() { return CheckNext(); } public static string String() { return Next(); } public static int Int() { return int.Parse(Next()); } public static long Long() { return long.Parse(Next()); } public static double Double() { return double.Parse(Next()); } public static int[] IntLine() { return Array.ConvertAll(Split(Line()), int.Parse); } public static int[] IntArray(int N) { return Range(N, Int); } public static int[][] IntTable(int H) { return Range(H, IntLine); } public static string[] StringArray(int N) { return Range(N, Next); } public static string[][] StringTable(int N) { return Range(N, () => Split(Line())); } public static string Line() { return reader.ReadLine().Trim(); } public static T[] Range(int N, Func f) { var r = new T[N]; for (int i = 0; i < N; r[i++] = f()) ; return r; } public static void Dispose() { reader.Dispose(); } static string[] Split(string s) { return s.Split(separator, op); } static string Next() { CheckNext(); return A[i++]; } static bool CheckNext() { if (i < A.Length) return true; string line = reader.ReadLine(); if (line == null) return false; if (line == "") return CheckNext(); A = Split(line); i = 0; return true; } }