using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

​

​

​

   public class duplictecharacters

    {

         public static void Main(string[] args)

        {

            Console.Write("Enter a String : ");

            string inputString = Console.ReadLine();

            string resString = string.Empty;

​

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

            {

                if (!resString.Contains(inputString[i]))

                {

                    resString += inputString[i];

                }

            }

            Console.WriteLine(resString);

​

            Console.ReadKey();

        }

    }

​