static void Main(string[] args)
{
DigitalClock digitalClock = new DigitalClock();
Console.WriteLine(digitalClock.DigitalClockInfo());
FlipClock flipClock = new FlipClock();
Console.WriteLine(flipClock.FlipClockInfo());
QuartzClock quartzClock = new QuartzClock();
Console.WriteLine(quartzClock.QuartzClockInfo());
}
