using System;

public class NumbersToWords

{

    public static string NumToWords(int number)

    {

        if (number == 0)

        return "zero";

​

    if (number < 0)

        return "minus " + NumToWords(Math.Abs(number));

​

    string words = "";

​

    if ((number / 1000000) > 0)

    {

        words += NumToWords(number / 1000000) + " million ";

        Console.WriteLine(words);

        number %= 1000000;

    }

​

    if ((number / 1000) > 0)

    {

        words += NumToWords(number / 1000) + " thousand ";

        Console.WriteLine(words);

        number %= 1000;

    }

​

    if ((number / 100) > 0)

    {

        words += NumToWords(number / 100) + " hundred ";

        Console.WriteLine(words);

        number %= 100;

    }

​

    if (number > 0)

    {

        var unitsMap = new[] { "zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine", "ten", "eleven", "twelve", "thirteen", "fourteen", "fifteen", "sixteen", "seventeen", "eighteen", "nineteen" };

        var tensMap = new[] { "zero", "ten", "twenty", "thirty", "forty", "fifty", "sixty", "seventy", "eighty", "ninety" };

​

        if (number < 20)

            words += unitsMap[number];

        else

        {

            words += tensMap[number / 10];

            if ((number % 10) > 0)

                words += "-" + unitsMap[number % 10];

        }

    }else{

        words = words.Trim();

    }

​

    return words; 

    }

    public static void Main()

    {

        Console.WriteLine(NumToWords(0));

        Console.WriteLine(NumToWords(1));

        Console.WriteLine(NumToWords(2));

        Console.WriteLine(NumToWords(3));

        Console.WriteLine(NumToWords(4));

        Console.WriteLine(NumToWords(5));

        Console.WriteLine(NumToWords(6));

        Console.WriteLine(NumToWords(7));

        Console.WriteLine(NumToWords(8));

        Console.WriteLine(NumToWords(9));

        Console.WriteLine(NumToWords(10));

        Console.WriteLine(NumToWords(11));

        Console.WriteLine(NumToWords(12));

        Console.WriteLine(NumToWords(13));

        Console.WriteLine(NumToWords(14));

        Console.WriteLine(NumToWords(15));

        Console.WriteLine(NumToWords(16));

        Console.WriteLine(NumToWords(17));

        Console.WriteLine(NumToWords(18));

        Console.WriteLine(NumToWords(19));

        Console.WriteLine(NumToWords(20));

        Console.WriteLine(NumToWords(22));

        Console.WriteLine(NumToWords(99));

        Console.WriteLine(NumToWords(100));

        Console.WriteLine(NumToWords(1000));

        Console.WriteLine(NumToWords(1999));

        Console.WriteLine(NumToWords(977653));

        Console.WriteLine(NumToWords(1000000));

    }

}