using System;

​

static class Globals

{

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

}

​

public class NewZealandMinistryofHealthNumber

{

    public static void Main()

    {

        bool isValid_oldformate = isValidNZMHN_oldformate("CGC2720");

        Console.WriteLine(isValid_oldformate);

        bool isValid_newformate = isValidNZMHN_newformate("DAB8233");

        Console.WriteLine(isValid_newformate);

    }

    private static bool authenticateAlphachars(string alpha)

    {

        char[] avoidchars = {'I','O'};

        foreach (char ch in avoidchars)

        {

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

            {

                if (ch.Equals(alpha[i]))

                {

                    return false;

                }

            }

        }

        return true;

    }

    private static int getReminder_oldformate(string nzmhn)

    {

        int flag;

        int addition = 0;

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

        {

            if (i < 3)

            {

                flag = 1;

                foreach (char ch in Globals.validchars)

                {

                    if (ch.Equals(nzmhn[i]))

                    {

                        addition += (flag * (7 - i));

                    }

                    flag++;

                }

            }

            else

            {

                addition += ((Convert.ToInt32(nzmhn[i]) - 48) * (7 - i));

            }           

        }

        int answer = 11 - addition % 11;

        if (answer == 0) return -1;

        if (answer == 10) return 0;

        return answer;

    }

    private static int getReminder_newformate(string nzmhn)

    {

        int flag;

        int addition = 0;

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

        {

            if (char.IsLetter(nzmhn[i]))

            {

                flag = 1;

                foreach (char ch in Globals.validchars)

                {

                    if (ch.Equals(nzmhn[i]))

                    {

                        addition += (flag * (7 - i));

                    }

                    flag++;

                }

            }

            else

            {

                addition += ((Convert.ToInt32(nzmhn[i]) - 48) * (7 - i));

            }

        }

        int answer = 24 - addition % 24;

        if (answer == 0) return -1;

        if (answer == 10) return 0;

        return answer;

    }

    private static bool isValidNZMHN_oldformate(string nzmhn)

    {

        if (nzmhn.Length != 7) return false;

        string alphachars = nzmhn.Substring(0, 3);

        if (!authenticateAlphachars(alphachars)) return false;

        int wholestring_check = Convert.ToInt32(nzmhn[nzmhn.Length - 1]) - 48;

        string wholestring = nzmhn.Substring(0, nzmhn.Length - 1);

        int wholestring_reminder = getReminder_oldformate(wholestring);

        if (wholestring_reminder != wholestring_check) return false;

        return true;

    }

    private static bool isValidNZMHN_newformate(string nzmhn)

    {

        if (nzmhn.Length != 7) return false;

        int wholestring_check = Convert.ToInt32(nzmhn[nzmhn.Length - 1]) - 48;

        string wholestring = nzmhn.Substring(0, nzmhn.Length - 1);

        if (!authenticateAlphachars(wholestring)) return false;

        int wholestring_reminder = getReminder_newformate(wholestring);

        if (wholestring_reminder != wholestring_check) return false;

        return true;

    }

}