using System;

​

public class Exercise1

{

    public static void Main( )

    {

         System.Console.WriteLine("Write your code at here");

        DateTime dateTime = DateTime.Now;

        string date = dateTime.ToString("dd/MM/yyyy");

        int dateNumber = Int32.Parse(date.Replace("/", ""));

        string pin = GenerateKeyValue(dateTime, dateNumber, 1);

        pin = pin.Replace('-', '0');

        if (pin.Length < 9)

        {

            pin = pin.PadLeft(9, '0');

        }

        string newPin = pin[pin.Length - 1].ToString() +

            pin[pin.Length - 3].ToString() +

            pin[pin.Length - 5].ToString() +

            pin[pin.Length - 7].ToString() +

            pin[pin.Length - 9].ToString();

        //Log.Debug("PIN RETURNED" + " ## " + newPin);

        System.Console.WriteLine("Generated Final Pin: "+ newPin);

    }

    public static string GenerateKeyValue(DateTime dateTime, int dateNumber, int version)

    {

        int day = dateTime.Day;

        int year = dateTime.Year;

        int month = dateTime.Month;

        System.Console.WriteLine("Day: "+day +"   Month: "+month  + "    Year :" +year   +   "    DayOfYear :" + dateTime.DayOfYear + "     dateNumber :" + dateNumber);

​

        if (version == 1)

        {

            System.Console.WriteLine("FirstPart :" + (dateNumber * ((day * month) + (day * year)))

                                    +" SecondPart :" + day

                                    +" ThirdPart :" + ((day * month) * day)

                                    +" FourthPart :" + (dateTime.DayOfYear - (month * day))

            );

            int cal = (dateNumber * ((day * month) + (day * year))) - day - ((day * month) * day) - (dateTime.DayOfYear - (month * day));

            System.Console.WriteLine(Convert.ToString(cal));

            return Convert.ToString(cal);

        }

        else if (version == 2)

        {

            return Convert.ToString((dateNumber * ((month * month) + (day * year))) - day - ((day * month) * day) - (dateTime.DayOfYear - (month * day)));

        }

        else if (version == 3)

        {

            return Convert.ToString((dateNumber * ((year * month) + (day * year))) - day - ((day * month) * day) - (dateTime.DayOfYear - (month * day)));

        }

        else

        {

            return GenerateKeyValue(dateTime, dateNumber, 1);

        }

    }

}