C# 1 Input to Output

[DOPEinDOPAMINE]

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


namespace jack
{
    class Program
    {
        /*
            Convert Decimal[1-9999] to Roman numerals in easy way.
            Hope it is Correct! No error handling is done!
            Writing a fuction is better!
        }*/
        static void Main(string[] args)
        {
            string[,] romanNo = new string[,] {{"", "I","II", "III", "IV", "V", "VI", "VII", "VIII", "IX"},
                                               {"", "X","XX","XXX","XL","L","LX","LXX","LXXX","XC"},
                                               {"", "C", "CC", "CCC", "CD", "D", "DC", "DCC", "DCCC", "CM" },
                                               {"", "M", "MM", "MMM", "MMMM", "MMMMM", "MMMMMM", "MMMMMMM", "MMMMMMMM", "MMMMMMMMM" }
            };
            static String NumWordsWrapper(double n)
            {
                string words = "";
                double intPart;
                double decPart = 0;
                if (n == 0)
                    return "zero";
                try
                {
                    string[] splitter = n.ToString().Split('.');
                    intPart = double.Parse(splitter[0]);
                    decPart = double.Parse(splitter[1]);
                }
                catch
                {
                    intPart = n;
                }

                words = NumWords(intPart);

                if (decPart > 0)
                {
                    if (words != "")
                        words += " and ";
                    int counter = decPart.ToString().Length;
                    switch (counter)
                    {
                        case 1: words += NumWords(decPart) + " tenths"; break;
                        case 2: words += NumWords(decPart) + " hundredths"; break;
                        case 3: words += NumWords(decPart) + " thousandths"; break;
                        case 4: words += NumWords(decPart) + " ten-thousandths"; break;
                        case 5: words += NumWords(decPart) + " hundred-thousandths"; break;
                        case 6: words += NumWords(decPart) + " millionths"; break;
                        case 7: words += NumWords(decPart) + " ten-millionths"; break;
                    }
                }
                return words;
            }

            static String NumWords(double n) //converts double to words
            {
                string[] numbersArr = new string[] { "one", "two", "three", "four", "five", "six", "seven", "eight", "nine", "ten", "eleven", "twelve", "thirteen", "fourteen", "fifteen", "sixteen", "seventeen", "eighteen", "nineteen" };
                string[] tensArr = new string[] { "twenty", "thirty", "fourty", "fifty", "sixty", "seventy", "eighty", "ninty" };
                string[] suffixesArr = new string[] { "thousand", "million", "billion", "trillion", "quadrillion", "quintillion", "sextillion", "septillion", "octillion", "nonillion", "decillion", "undecillion", "duodecillion", "tredecillion", "Quattuordecillion", "Quindecillion", "Sexdecillion", "Septdecillion", "Octodecillion", "Novemdecillion", "Vigintillion" };
                string words = "";

                bool tens = false;

                if (n < 0)
                {
                    words += "negative ";
                    n *= -1;
                }

                int power = (suffixesArr.Length + 1) * 3;

                while (power > 3)
                {
                    double pow = Math.Pow(10, power);
                    if (n >= pow)
                    {
                        if (n % pow > 0)
                        {
                            words += NumWords(Math.Floor(n / pow)) + " " + suffixesArr[(power / 3) - 1] + ", ";
                        }
                        else if (n % pow == 0)
                        {
                            words += NumWords(Math.Floor(n / pow)) + " " + suffixesArr[(power / 3) - 1];
                        }
                        n %= pow;
                    }
                    power -= 3;
                }
                if (n >= 1000)
                {
                    if (n % 1000 > 0) words += NumWords(Math.Floor(n / 1000)) + " thousand, ";
                    else words += NumWords(Math.Floor(n / 1000)) + " thousand";
                    n %= 1000;
                }
                if (0 <= n && n <= 999)
                {
                    if ((int)n / 100 > 0)
                    {
                        words += NumWords(Math.Floor(n / 100)) + " hundred";
                        n %= 100;
                    }
                    if ((int)n / 10 > 1)
                    {
                        if (words != "")
                            words += " ";
                        words += tensArr[(int)n / 10 - 2];
                        tens = true;
                        n %= 10;
                    }

                    if (n < 20 && n > 0)
                    {
                        if (words != "" && tens == false)
                            words += " ";
                        words += (tens ? "-" + numbersArr[(int)n - 1] : numbersArr[(int)n - 1]);
                        n -= Math.Floor(n);
                    }
                }

                return words;

            }
            Console.Write("Input between 0 an 9999 : ");
            string digitSt = Console.ReadLine();

            string st = "";
            for (int i = digitSt.Length - 1; i >= 0; i--)
                st += romanNo[i, int.Parse(digitSt[digitSt.Length - 1 - i].ToString())];
            st = string.Format("Number in Roman Numerals = {1}", digitSt, st);




            Double n = Double.Parse(Console.ReadLine());

            Console.WriteLine("Number in words: {0}", NumWordsWrapper(n));

            Console.WriteLine(st);


 

        }
    }
}

Dapat sana isang input question lang pa help po