using System;

public class SloveniaNationalIdentificationNumber

{

    public static void Main()

    {

        bool isValid = isValidSNIN("0101006500006");

        Console.WriteLine(isValid);

    }

    private static bool authenticateMonth(int month)

    {

        if (month >= 1 && month <= 12) return true; 

        return false;

    }

    private static bool authenticateDate(int date)

    {

        if (date < 1 || date > 31) return false;

        return true;

    }

    private static bool authenticateConstant(int c)

    {

        if (c != 50) return false;      

        return true;

    }

    private static int getReminder(string snin)

    {

        int addition = 0;

        for (int i=0;i<(snin.Length/2);i++)

        {

            addition += ((Convert.ToInt32(snin[i]) - 48) + (Convert.ToInt32(snin[(snin.Length / 2)+ i]) - 48)) * (7 - i);

        }

        int answer = 11 - addition % 11;

        if (answer == 10 || answer == 11) return 0;

        return answer;

    }

    private static bool isValidSNIN(string snin)

    {

        if (snin.Length != 13) return false;

        foreach(char ch in snin)

        {

            if (char.IsLetter(ch)) return false;

        }

        int date = Convert.ToInt32(snin.Substring(0,2));

        if (!authenticateDate(date)) return false;

        int month = Convert.ToInt32(snin.Substring(2,2));

        if (!authenticateMonth(month)) return false;

        int constant = Convert.ToInt32(snin.Substring(7,2));

        if (!authenticateConstant(constant)) return false;

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

​

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

        int wholestring_reminder = getReminder(wholestring);

        if (wholestring_reminder != wholestring_check) return false;

        return true;

    }

}