void Start()
{
IPencil pencil = new Pencil(20);
IPencilSharpener pencilSharpener = new PencilSharpener();
string input;
while (true)
{
Console.Write("Enter a word: ");
input = Console.ReadLine();
if (input == "stop")
{
return;
}
if (input == "sharpen")
{
pencilSharpener.Sharpen(pencil);
}
else
{
pencil.Write(input);
}
}
}