using System;

public class Program

{

    static void checkAge(int age)

    {

        if (age < 18)

        {

            throw new ArithmeticException("Access denied - you muse be at least 18 years of age!");

        }

        else

        {

            Console.WriteLine("Access granted - you are old enough");

        }

    }

    public static void Main()

    {

        checkAge(21);

    }

}