using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace _15_numbersToText
{
    class NumToText
    {
        static void Main(string[] args)
        {
            // user input
            int number = 0;
            try
            {
                number = int.Parse(Console.ReadLine());
            }
            catch (Exception)
            {
                Console.WriteLine("invalid number");
            }


            // defiine variables
            string numbersToWords = "";

            // building the class
            NumToText n = new NumToText();

            // determine the structure of the user input
            if ( number == 100 )
            {
                // if hundred
                numbersToWords = "one hundred";
            }
            else if ( number < 10 )
            {
                // if under 10
                numbersToWords = n.UnitsToText(number);
            }
            else if ( number > 9 && number < 20 )
            {
                // if between 11 - 19 inclusively
                numbersToWords = n.TeenNumsToText(number);
            }
            else if (number > 19 && number < 100)
            {
                // if between 20 and 99 inclusively
                string uw = ""; // units
                string tw = ""; // tens

                // get the whole number
                int tens = (number / 10) * 10;
                tw = n.TensToText(tens);

                // get the units after the whole number
                int modul = number % 10;

                if(modul > 0)
                {
                    uw = n.UnitsToText(modul);
                    uw = " " + uw;
                }

                numbersToWords = tw + uw;
            }
            else
            {
                numbersToWords = "invalid number";
            }


            Console.WriteLine(numbersToWords);
        }

        public string UnitsToText (int num1)
        {
            // return units to text
            string toWord = "";

            switch (num1)
            {
                case 1:     toWord = "one";     break;
                case 2:     toWord = "two";     break;
                case 3:     toWord = "three";   break;
                case 4:     toWord = "four";    break;
                case 5:     toWord = "five";    break;
                case 6:     toWord = "six";     break;
                case 7:     toWord = "seven";   break;
                case 8:     toWord = "eight";   break;
                case 9:     toWord = "nine";    break;
                case 0:     toWord = "zero";    break;
                default:    toWord = "NaN";     break;
            }

            return toWord;
        }

        public string TeenNumsToText (int num1)
        {
            // return units to text
            string toWord = "";

            switch (num1)
            {
                case 11: toWord = "eleven"; break;
                case 12: toWord = "twelve"; break;
                case 13: toWord = "thirteen"; break;
                case 14: toWord = "fourteen"; break;
                case 15: toWord = "fifteen"; break;
                case 16: toWord = "sixteen"; break;
                case 17: toWord = "seventeen"; break;
                case 18: toWord = "eightteen"; break;
                case 19: toWord = "nineteen"; break;
                default: toWord = "NaN"; break;
            }

            return toWord;
        }

        public string TensToText (int num1)
        {
            // return tens to text
            string toWord = "";

            switch (num1)
            {
                case 20:    toWord = "twenty";     break;
                case 30:    toWord = "thirty";     break;
                case 40:    toWord = "fourty";     break;
                case 50:    toWord = "fifty";      break;
                case 60:    toWord = "sixty";      break;
                case 70:    toWord = "seventy";    break;
                case 80:    toWord = "eightty";    break;
                case 90:    toWord = "ninety";     break;
                default:    toWord = "NaN";        break;
            }

            return toWord;
        }
    }
}