public static void Main()
Console.WriteLine("Number to words");
Console.WriteLine("Input a number to convert: ");
convertNumber = Console.ReadLine();
if (Int32.TryParse(convertNumber, out number) == false)
Console.WriteLine("Invalid number. Please input a positive integer.");
Console.WriteLine("One thousand");
Console.WriteLine("Zero");
word = word + " seventy";
word = word + " thirteen";
word = word + " fourteen";
word = word + " fifteen";
word = word + " sixteen";
word = word + " seventeen";
word = word + " eighteen";
word = word + " nineteen";