using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        string word = "abbabbaabbabbaabbabba";

        var suffix = "";

        var prefix = "";

        var dictionary = new Dictionary<string, int>();

        var longestCommonString = "";

        for (int i = 0, l = word.Length - 1; i < word.Length; i++, l--) {

            prefix += word[i];

            suffix = String.Concat(word[l], suffix);

            if (dictionary.ContainsKey(prefix)) {

                dictionary[prefix] = dictionary[prefix] + 1;

            } else {

                dictionary.Add(prefix, 1);

            }

            if (dictionary.ContainsKey(suffix)) {

                dictionary[suffix] = dictionary[suffix] + 1;

            } else {

                dictionary.Add(suffix, 1);

            }

            if (prefix == suffix) {

                Console.WriteLine(longestCommonString);

                if (longestCommonString.Length < prefix.Length && prefix != word) {

                    longestCommonString = prefix; 

                }

                continue;

            }

            if(dictionary.ContainsKey(suffix) && dictionary.ContainsKey(prefix) && dictionary[suffix] > 1 && dictionary[prefix] > 1) {

                if (longestCommonString.Length < prefix.Length && prefix != word) {

                    longestCommonString = prefix; 

                }

                continue;

            }

        }

        Console.WriteLine(longestCommonString);

        Console.WriteLine(longestCommonString.Length);

    }

}