static void TossSixTimes(ThreeCoins threeCoins)
 {
     for (int i = 0; i < 6; i++)
     {
         threeCoins.TossAndDraw();
         Console.WriteLine($"{(threeCoins.Coin1.IsYangSideUp ? 3 : 2)} " +
                           $"{(threeCoins.Coin2.IsYangSideUp ? 3 : 2)} " +
                           $"{(threeCoins.Coin3.IsYangSideUp ? 3 : 2)}");
     }
 }
        static void Main()
        {
            var threeCoins = new ThreeCoins(new Paper());

            TossSixTimes(threeCoins);
            var paintings = threeCoins.Paper.GetPaintings();

            Console.WriteLine($"{paintings.Original} -> {paintings.Changed}");

            Console.WriteLine();

            // To use a new empty paper to record.
            threeCoins.Paper = new Paper();
            TossSixTimes(threeCoins);
            paintings = threeCoins.Paper.GetPaintings();
            Console.WriteLine($"{paintings.Original} -> {paintings.Changed}");
        }