using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Remove duplicates from a string");

        var astring = Console.ReadLine();

        Console.WriteLine(RemoveDuplicateChars(astring));

    }

    public static string RemoveDuplicateChars(string inputString)

    {

        var table="";

        var result="";

        foreach(char c in inputString)

        {

            if(table.IndexOf(c) == -1)

            {

                table+=c;

                result+=c;

            }

        }

        return result;

    }   

}