using System;

public class Program

{

    public static void Main()

    {

        string cusip = "373384VP"; //enter 8 digit cusip here

        string checkDigit = GenerateCheckDigit(cusip);

        Console.WriteLine("Cusip: {0}", cusip);

        Console.WriteLine("Check: {0}", checkDigit);

        Console.WriteLine("Final: {0}{1}", cusip, checkDigit);

    }

    public static string GenerateCheckDigit(string cusip)

    {        

        int sum = 0;

        char[] digits = cusip.ToUpper().ToCharArray();

        string alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ*@#";

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

        {

            int val;

            if (!int.TryParse(digits[i].ToString(), out val))

                val = alphabet.IndexOf(digits[i]) + 10;

            if ((i % 2) != 0)

                val *= 2;

            val = (val % 10) + (val / 10);

            sum += val;

        }

        int check = (10 - (sum % 10)) % 10;

        return check.ToString();

    }

}