NumberAsWords

using System;


class NumberAsWords
{
    static void Main()
    {
        Console.Write("Please eneter a number between 0 - 999: ");
        Console.Write("");
        int a = int.Parse(Console.ReadLine());

        if (a >= 100 && a < 1000)
        {
            if (a >= 100 && a < 200)
            {
                Console.Write("One");
            }
            else if (a >= 200 && a < 300)
            {
                Console.Write("Two");
            }
            else if (a >= 300 && a < 400)
            {
                Console.Write("Three");
            }
            else if (a >= 400 && a < 500)
            {
                Console.Write("Four");
            }
            else if (a >= 500 && a < 600)
            {
                Console.Write("Five");
            }
            else if (a >= 600 && a < 700)
            {
                Console.Write("Six");
            }
            else if (a >= 700 && a < 800)
            {
                Console.Write("Seven");
            }
            else if (a >= 800 && a < 900)
            {
                Console.Write("Eight");
            }
            else if (a >= 900 && a < 1000)
            {
                Console.Write("Nine");
            }
            Console.Write(" Hundred");
        }

        if ((a >= 10 && a < 20) || (a % 100 >= 10 && a % 100 < 20))
        {
            if (a >= 100 && a < 1000 && a % 100 != 0)
            {
                Console.Write(" and ");
            }

            int n = a % 100;
            switch (n)
            {
                case 10:
                    Console.Write("Ten");
                    break;
                case 11:
                    Console.Write("Eleven");
                    break;
                case 12:
                    Console.Write("Тwelve");
                    break;
                case 13:
                    Console.Write("Thirteen");
                    break;
                case 14:
                    Console.Write("Fourteen");
                    break;
                case 15:
                    Console.Write("Fifteen");
                    break;
                case 16:
                    Console.Write("Sixteen");
                    break;
                case 17:
                    Console.Write("Seventeen");
                    break;
                case 18:
                    Console.Write("Eighteen");
                    break;
                case 19:
                    Console.Write("Nineteen");
                    break;
            }
            return;
        }

        if ((a >= 20 && a < 100) || (a % 100 >= 20 && a % 100 < 100))
        {
            if (a >= 100 && a < 1000 && a % 100 != 0)
            {
                Console.Write(" and ");
            }

            int n = a % 100;
            if (n >= 20 && n < 30)
            {
                Console.Write("Twenty");
            }
            else if (n >= 30 && n < 40)
            {
                Console.Write("Thirty");
            }
            else if (n >= 40 && n < 50)
            {
                Console.Write("Fourty");
            }
            else if (n >= 50 && n < 60)
            {
                Console.Write("Fifty");
            }
            else if (n >= 60 && n < 70)
            {
                Console.Write("Sixty");
            }
            else if (n >= 70 && n < 80)
            {
                Console.Write("Seventy");
            }
            else if (n >= 80 && n < 90)
            {
                Console.Write("Eighty");
            }
            else if (n >= 90 && n < 100)
            {
                Console.Write("Ninety");
            }
        }

        if ((a >= 0 && a <= 9) || (a % 10 >= 0 && a % 10 <= 9))
        {
            if ((a >= 10 && a < 100) || (a % 100 >= 10 && a % 100 < 100))
            {
                Console.Write(" ");
            }
            else if (a >= 100 && a < 1000 && a % 10 != 0)
            {
                Console.Write(" and ");
            }

            int n = a % 10;
            switch (n)
            {
                case 1:
                    Console.Write("One");
                    break;
                case 2:
                    Console.Write("Two");
                    break;
                case 3:
                    Console.Write("Three");
                    break;
                case 4:
                    Console.Write("Four");
                    break;
                case 5:
                    Console.Write("Five");
                    break;
                case 6:
                    Console.Write("Six");
                    break;
                case 7:
                    Console.Write("Seven");
                    break;
                case 8:
                    Console.Write("Eight");
                    break;
                case 9:
                    Console.Write("Nine");
                    break;
            }
        }

        if (a == 0)
        {
            Console.Write("Zero");
        }
    }
}