// Andrew Vasilyev, 2010
using System;

namespace rubytrolling
{
    public static class IntExtension
    {
        public static void Times(this int value, Action action)
        {
            if (action == null) throw new ArgumentNullException("action");
            for (var i = 0; i < value; i++)
                action();
        }

        public static void UpTo(this int value, int to, Action<int> action)
        {
            if (action == null) throw new ArgumentNullException("action");
            for (var i = value; i <= to; i++)
                action(i);
        }

        public static void DownTo(this int value, int to, Action<int> action)
        {
            if (action == null) throw new ArgumentNullException("action");
            for (var i = value; i >= to; i--)
                action(i);
        }
    }

    class Program
    {
        static void Main()
        {
            10.Times(() => Console.WriteLine("Hello"));
            5.UpTo(10, Console.WriteLine);
            10.DownTo(5, Console.WriteLine);

            1.UpTo(5,
                i => 1.UpTo(5,
                    j => Console.WriteLine(i * j)
                )
            );
        }
    }
}