using System;

public class Program

{

    public static void Main()

    {

        string grairesult = To170BitFormat("0540011105866538436");

        System.Console.WriteLine(grairesult);

        grairesult = To170BitFormat("80030540011105866538436");

        System.Console.WriteLine(grairesult);

    }

        private const string Prefix = "8003"; //8003 + 05400111058665023003

        private const int PrefixLength = 4; //8003 + 05400111058665023003

        private const int PaddingZeroLength = 1; //8003 + 0 + 5400111058665023003

        private const int EanLength = 13; //80030 + 5400111058665 + 023003

        private const int SerialNumberLength170Bit = 6; //800305400111058665 + 023003

        private const string NinoveRollCarEan = "5400111058665";

        public static string To170BitFormat(string grai)

        {

            string result = grai;

            int preSerialNumberLength = PrefixLength + PaddingZeroLength + EanLength;

            if (grai != null && grai.StartsWith(Prefix) && grai.Length >= preSerialNumberLength && grai.Substring(PrefixLength + PaddingZeroLength, EanLength) == NinoveRollCarEan)

            {

​

                result = grai.Substring(0, preSerialNumberLength) + grai.Substring(preSerialNumberLength).PadLeft(SerialNumberLength170Bit, '0');

            }

​

            return result;

        }

​

}