using System;

public class Program

{

        private static String[] lowNames = {

     "zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine", "ten",

     "eleven", "twelve", "thirteen", "fourteen", "fifteen", "sixteen", "seventeen", "eighteen", "nineteen"};

​

        private static String[] tensNames = {

      "twenty", "thirty", "forty", "fifty", "sixty", "seventy", "eighty", "ninety"};

​

        private static String[] bigNames = {

      "thousand", "million", "billion"};

        public static void Main()

        {

            Console.WriteLine(convertNumberToWords(1000));

        }

    public static String convertNumberToWords (int n) {

   if (n < 0) {

      return "minus " + convertNumberToWords(-n); }

   if (n <= 999) {

      return convert999(n); }

   String s = null;

   int t = 0;

   while (n > 0) {

      if (n % 1000 != 0) {

         String s2 = convert999(n % 1000);

         if (t > 0) {

            s2 = s2 + " " + bigNames[t-1]; }

         if (s == null) {

            s = s2; }

          else {

            s = s2 + ", " + s; }}

      n /= 1000;

      t++; }

   return s; }

    private static String convert999 (int n) {

   String s1 = lowNames[n / 100] + " hundred";

   String s2 = convert99(n % 100);

   if (n <= 99) {

      return s2; }

    else if (n % 100 == 0) {

      return s1; }

    else {

      return s1 + " " + s2; }}

    private static String convert99 (int n) {

   if (n < 20) {

      return lowNames[n]; }

   String s = tensNames[n / 10 - 2];

   if (n % 10 == 0) {

      return s; }

   return s + "-" + lowNames[n % 10]; }

}