Numbers as Words

using System;

class NumbersAsWords
{
    static void Main()
    {
        int number = int.Parse(Console.ReadLine());
        int number0to20 = number % 100;
        int units = number % 10;
        int tens = (number / 10) % 10;
        int hundreds = (number / 100) % 10;
        string result = "";

        string[] unitsAsWods = { "", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine", "ten",
                            "eleven", "twelve", "thirteen", "fourten", "fifteen", "sixteen", "seventeen", "eighteen", "nineteen"};
        string[] tensAsWords = { "", "", "twenty", "thirty", "fourty", "fifty", "sixty", "seventy","eighty", "ninety" };
        string[] hundredsAsWords = { "", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine" };


        if (units == 0 && tens == 0 && hundreds == 0)
        {
            Console.WriteLine("zero");
            return;
        }

        string and = "";
        if (hundreds > 0 && number0to20 > 0)
        {
            and = " and ";
        }

        if (number0to20 < 20)
        {
            result = string.Format("{0}{1}{2}{3}", hundredsAsWords[hundreds], hundreds == 0 ? "" : " hundred", and, unitsAsWods[number0to20]);
        }
        else
        {
            result = string.Format("{0}{1}{2}{3} {4}", hundredsAsWords[hundreds], hundreds == 0 ? "" : " hundred",
                           and, tensAsWords[tens], unitsAsWods[units]);
        }

        Console.WriteLine(result);
    }

}