using System;

public class IrelandNationalIdentificationNumber

{

    public static void Main()

    {

        bool isValid = isValidININ("1234567TW");

        Console.WriteLine(isValid);

    }

    private static string getReminder(string inin)

    {

        int addition = 0;

        for (int i=0;i<inin.Length - 1;i++)

        {

            addition += (Convert.ToInt32(inin[i]) - 48) * (inin.Length - i);

            Console.WriteLine(addition);

        }

        char[] alphabets = {'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z'};

        int start = 1;

​

        foreach (char ch in alphabets)

        {

            if (ch.Equals(inin[inin.Length - 1]))

            {

                addition += start * 9;

            }

            start += 1;

        }

        int answer = addition % 23;

        if (answer == 0) return "W";

        return ((char)(answer + 64)).ToString();

    }

    private static bool isValidININ(string inin)

    {

        if (inin.Length != 9) return false;

        string wholestring_check = inin[7].ToString();

        string wholestring = inin.Remove(inin.Length - 2,1);

        string wholestring_reminder = getReminder(wholestring);

        if (!wholestring_reminder.Equals(wholestring_check)) return false;

        return true;

    }

}