To100byWords

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

namespace Test
{
    class BeerTime
    {
        static void Main(string[] args)
        {
            int n = int.Parse(Console.ReadLine());

            switch(n)
            {
                case 0:
                    Console.WriteLine("zero");
                    break;
                case 1:
                    Console.WriteLine("one");
                    break;
                case 2:
                    Console.WriteLine("two");
                    break;
                case 3:
                    Console.WriteLine("three");
                    break;
                case 4:
                    Console.WriteLine("four");
                    break;
                case 5:
                    Console.WriteLine("five");
                    break;
                case 6:
                    Console.WriteLine("six");
                    break;
                case 7:
                    Console.WriteLine("seven");
                    break;
                case 8:
                    Console.WriteLine("eight");
                    break;
                case 9:
                    Console.WriteLine("nine");
                    break;
                case 10:
                    Console.WriteLine("ten");
                    break;
                case 11:
                    Console.WriteLine("eleven");
                    break;
                case 12:
                    Console.WriteLine("twelve");
                    break;
                case 13:
                    Console.WriteLine("thirteen");
                    break;
                case 14:
                    Console.WriteLine("fourteen");
                    break;
                case 15:
                    Console.WriteLine("fifteen");
                    break;
                case 16:
                    Console.WriteLine("sixteen");
                    break;
                case 17:
                    Console.WriteLine("seventeen");
                    break;
                case 18:
                    Console.WriteLine("eighteen");
                    break;
                case 19:
                    Console.WriteLine("nineteen");
                    break;
                default:
                    break;
            }

            if(n >= 20)
            {
                int a = n / 10;

                switch(a)
                {
                    case 2:
                        Console.Write ("twenty");
                        break;
                    case 3:
                        Console.Write("thirty");
                        break;
                    case 4:
                        Console.Write("fourty");
                        break;
                    case 5:
                        Console.Write("fifty");
                        break;
                    case 6:
                        Console.Write("sixty");
                        break;
                    case 7:
                        Console.Write("seventy");
                        break;
                    case 8:
                        Console.Write("eighty");
                        break;
                    case 9:
                        Console.Write("ninety");
                        break;
                }

                a = n % 10;

                switch(a)
                {
                    case 1:
                        Console.WriteLine(" one");
                        break;
                    case 2:
                        Console.WriteLine(" two");
                        break;
                    case 3:
                        Console.WriteLine(" three");
                        break;
                    case 4:
                        Console.WriteLine(" four");
                        break;
                    case 5:
                        Console.WriteLine(" five");
                        break;
                    case 6:
                        Console.WriteLine(" six");
                        break;
                    case 7:
                        Console.WriteLine(" seven");
                        break;
                    case 8:
                        Console.WriteLine(" eight");
                        break;
                    case 9:
                        Console.WriteLine(" nine");
                        break;
                    default:
                        break;
                }
            }
        }
    }
}