using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        var data = "abcdbcdef".ToCharArray();

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

        var finalList = new List<string>();

        for(var i=0; i<data.Length; i++)

        {

            dicData.Add(i, new List<string>());

            var currentValue = "";

            for (var j=i; j<data.Length; j++)

            {

                currentValue = currentValue + data[j].ToString();

                var currentList = dicData[i];

                currentList.Add(currentValue);

                dicData[i] = currentList;

                //Console.WriteLine(currentValue);

            }

            //Console.WriteLine("=====================================");

        }

        for (var i=0; i< dicData.Count; i++)

        {

            finalList.AddRange(dicData[i]);

        }

        //Console.WriteLine(finalList.Count);

        var duplicates = new List<string>();

        for (var i=0; i<finalList.Count; i++)

        {

            for (var j=i+1; j<finalList.Count; j++)

            {

                if (finalList[i] == finalList[j])

                {

                    //Console.WriteLine("i"+i+": "+finalList[i]);

                    //Console.WriteLine("j"+j+": "+finalList[j]);

                    duplicates.Add(finalList[i]);

                    Console.WriteLine(finalList[i]);

                }

            }

        }

        Console.WriteLine("Hello World");

    }

}