using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace No273
{
	class MainClass
	{
		public static void Main (string[] args)
		{
			var s = Console.ReadLine ();

			int maxMatch = 1;
			for (int i = 1; i < s.Length; i++) {
				for (int k = i + 1; k < s.Length; k++) {
					bool match = true;
					for (int j = 0; j + i <= k; j++) {
						if (s [i + j] != s [k - j]) {
							match = false;
							break;
						}
					}
					if (match) {
						maxMatch = Math.Max (maxMatch, k - i + 1);
					}
				}
			}
			for (int i = 0; i < s.Length - 1; i++) {
				for (int k = i + 1; k < s.Length - 1; k++) {
					bool match = true;
					for (int j = 0; j + i <= k; j++) {
						if (s [i + j] != s [k - j]) {
							match = false;
							break;
						}
					}
					if (match) {
						maxMatch = Math.Max (maxMatch, k - i + 1);
					}
				}
			}
			Console.WriteLine (maxMatch.ToString ());
		}
	}
}