using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        string sample = "lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.";

        char? result = FirstNonRepeatedCharacter(sample);

        Console.WriteLine("'{0}' is the first non-repeated character in the string \"{1}\"", result, sample);

    }

    public static char? FirstNonRepeatedCharacter(string text) 

    {   

        if(string.IsNullOrEmpty(text)

           {

               return '\0';

           }

          if(text.Length == 1)

           {

               return text[0];

           }

           Dictionary<char, int> strIdentifier = new Dictionary<char, int>();

           for(int i=0; i < text.Length; i++)

           {

               if(strIdentifier.ContainsKey(text[i]))

                  {

                      strIdentifier[text[i]]++;

                  }

                  else

                  {

                      strIdentifier.Add(text[i], 1);

                  }            

           }

           for(int j=0; j

        return null;

    }

}