using System; using System.Collections.Generic; using System.Diagnostics; using System.IO; using System.Linq; using System.Numerics; using System.Text; using static System.Math; using static System.Linq.Enumerable; using static Extentions; using static System.Console; public static class Program { #region Scanners static Scanner _scanner; static char C => _scanner.NextChar(); static string S => _scanner.NextString(); static int I => _scanner.NextInt(); static long L => _scanner.NextLong(); static BigInteger B => _scanner.NextBigInteger(); static double D => _scanner.NextDouble(); static decimal M => _scanner.NextDecimal(); #endregion public static void Solve() { var s = S; var ans = 0; for (var i = 0; i < s.Length; i++) { var l = Min(i, s.Length - i - 1); var cnt1 = 0; for (var j = 1; j <= l; j++) if (s[i - j] == s[i + j]) cnt1++; ans = Max(ans, cnt1); var cnt2 = 0; for (var j = 1; j <= l; j++) if (s[i - j] == s[i + j - 1]) cnt2++; ans = Max(ans, cnt2); } WriteLine(ans * 2 + 1); } public static void Main() { Console.SetOut(new StreamWriter(Console.OpenStandardOutput()) { NewLine = "\n", #if DEBUG AutoFlush = true, #else AutoFlush = false, #endif }); _scanner = new Scanner(Console.OpenStandardInput()); Solve(); Console.Out.Flush(); } } public static partial class Extentions { } #region Library // not tested public class Scanner { private readonly Stream _stream; private const int _bufferSize = 1024; private readonly byte[] _buf = new byte[_bufferSize]; private int _len, _ptr; public Scanner(Stream stream) { _stream = stream; } public byte ReadByte() { if (_ptr >= _len) { _len = _stream.Read(_buf, 0, 1024); _ptr = 0; } return _buf[_ptr++]; } public char ReadChar() => (char)ReadByte(); public string ReadLine() { var r = new StringBuilder(); if (_ptr == 0) r.Append(ReadChar()); for (; _ptr < _len; _ptr++) r.Append((char)_buf[_ptr]); return r.ToString(); } public char NextChar() => char.Parse(NextString()); public string NextString() { var r = new StringBuilder(); var b = ReadChar(); while (b != ' ' && b != '\n') { r.Append(b); b = ReadChar(); } return r.ToString(); } public int NextInt() => (int)NextLong(); public long NextLong() { var r = 0L; var b = ReadByte(); var n = b == '-'; if (n) b = ReadByte(); while (b != ' ' && b != '\n') { r = r * 10 + b - '0'; b = ReadByte(); } return n ? -r : r; } public BigInteger NextBigInteger() { var r = new BigInteger(); var b = ReadByte(); var n = b == '-'; if (n) b = ReadByte(); while (b != ' ' && b != '\n') { r = r * 10 + b - '0'; b = ReadByte(); } return n ? -r : r; } public double NextDouble() { var i = 0L; var b = ReadByte(); var n = b == '-'; if (n) b = ReadByte(); while (b != '.') { i = i * 10 + b - '0'; b = ReadByte(); } var f = 0L; var p = 0; while (b != ' ' && b != '\n') { f = f * 10 + b - '0'; b = ReadByte(); p++; } var r = i + f / Pow(10.0, p); return n ? -r : r; } public decimal NextDecimal() => decimal.Parse(NextString()); public T Next(Func parser) => parser(NextString()); } public static partial class Extentions { public static void Assert(bool condition) { if (!condition) throw new Exception(); } public static string AsString(this IEnumerable source) => new string(source.ToArray()); public static void ForEach(this IEnumerable source, Action action) { foreach (var item in source) action(item); } public static void ForEach(this IEnumerable source, Func func) { foreach (var item in source) func(item); } public static void ForEach(this IEnumerable source, Action action) { var i = 0; foreach (var item in source) action(item, i++); } public static void ForEach(this IEnumerable source, Func func) { var i = 0; foreach (var item in source) func(item, i++); } public static void Repeat(int count, Action action) { for (var i = 0; i < count; i++) action(); } public static void Repeat(int count, Action action) { for (var i = 0; i < count; i++) action(i); } public static IEnumerable Repeat(Func func) { for (var i = 0; ; i++) yield return func(); } public static IEnumerable Repeat(int count, Func func) { for (var i = 0; i < count; i++) yield return func(); } public static IEnumerable Repeat(Func func) { for (var i = 0; ; i++) yield return func(i); } public static IEnumerable Repeat(int count, Func func) { for (var i = 0; i < count; i++) yield return func(i); } public static void Swap(ref T x, ref T y) { var tmp = x; x = y; y = tmp; } } #endregion