static void Main(string[] args)
{
InstrumentFactory factory = new ConcreteInstrumentFactory();
IInstrument guitar = factory.GetInstrument("Guitar");
guitar.Play(96);
guitar.Sell(120);
IInstrument piano = factory.GetInstrument("Piano");
piano.Play(80);
piano.Sell(1000);
IInstrument bass = factory.GetInstrument("Bass");
bass.Play(75);
bass.Sell(150);
}
