diff --git a/Examples/CryptoCurrencyExternalLibrary/CryptoCurrency.cs b/Examples/CryptoCurrencyExternalLibrary/CryptoCurrency.cs
new file mode 100644
index 0000000..09c68c7
--- /dev/null
+++ b/Examples/CryptoCurrencyExternalLibrary/CryptoCurrency.cs
@@ -0,0 +1,17 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace CryptoCurrencyExternalLibrary
+{
+    public class CryptoCurrency
+    {
+        public decimal ExternalProcessPayment(decimal amount)
+        {
+            return amount;
+        }
+
+    }
+}
diff --git a/Examples/CryptoCurrencyExternalLibrary/CryptoCurrencyExternalLibrary.csproj b/Examples/CryptoCurrencyExternalLibrary/CryptoCurrencyExternalLibrary.csproj
new file mode 100644
index 0000000..fa71b7a
--- /dev/null
+++ b/Examples/CryptoCurrencyExternalLibrary/CryptoCurrencyExternalLibrary.csproj
@@ -0,0 +1,9 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>
diff --git a/Examples/Examples.sln b/Examples/Examples.sln
index 0fd3d0a..21724c1 100644
--- a/Examples/Examples.sln
+++ b/Examples/Examples.sln
@@ -3,13 +3,15 @@ Microsoft Visual Studio Solution File, Format Version 12.00
 # Visual Studio Version 17
 VisualStudioVersion = 17.8.35430.204
 MinimumVisualStudioVersion = 10.0.40219.1
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "UserCode", "..\UserCode\UserCode.csproj", "{03E39C4B-5B4C-4FD2-A79D-AC86704AF3DC}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "UserCode", "..\UserCode\UserCode.csproj", "{03E39C4B-5B4C-4FD2-A79D-AC86704AF3DC}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ExternalClassLibrary", "..\ExternalClassLibrary\ExternalClassLibrary.csproj", "{B77A43A4-BF8D-44E1-B3E8-8F6DD365DEAB}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "ExternalClassLibrary", "..\ExternalClassLibrary\ExternalClassLibrary.csproj", "{B77A43A4-BF8D-44E1-B3E8-8F6DD365DEAB}"
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "RealExample", "RealExample", "{BEFC8EDE-A568-4AC3-B3EA-B68427103370}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Payment", "..\Payment\Payment.csproj", "{E7F0B3A7-6105-43CB-B4E1-3733111D4EB8}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Payment", "..\Payment\Payment.csproj", "{E7F0B3A7-6105-43CB-B4E1-3733111D4EB8}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "CryptoCurrencyExternalLibrary", "CryptoCurrencyExternalLibrary\CryptoCurrencyExternalLibrary.csproj", "{CEE91381-0168-4615-9DFA-0440BF0A4085}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
@@ -29,6 +31,10 @@ Global
 		{E7F0B3A7-6105-43CB-B4E1-3733111D4EB8}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{E7F0B3A7-6105-43CB-B4E1-3733111D4EB8}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{E7F0B3A7-6105-43CB-B4E1-3733111D4EB8}.Release|Any CPU.Build.0 = Release|Any CPU
+		{CEE91381-0168-4615-9DFA-0440BF0A4085}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{CEE91381-0168-4615-9DFA-0440BF0A4085}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{CEE91381-0168-4615-9DFA-0440BF0A4085}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{CEE91381-0168-4615-9DFA-0440BF0A4085}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
diff --git a/UserCode/Program.cs b/UserCode/Program.cs
index 1dd825f..492dc0c 100644
--- a/UserCode/Program.cs
+++ b/UserCode/Program.cs
@@ -70,6 +70,8 @@
 //    }
 //}
 
+
+
 //#endregion
 
 //#region 1.2
@@ -530,109 +532,271 @@
 //#endregion
 
 
-#region 1.8
+//#region 1.8
+
+//using CryptoCurrencyExternalLibrary;
+//using ExternalClassLibrary;
+//using System.ComponentModel;
+
+//public class Program
+//{
+//    public static void Main()
+//    {
+//        var type = Console.ReadLine();
+//        ITransport transport = TransportService.Create(type);
+//        transport.Send();
+//    }
+//}
+
+//public class TransportService
+//{
+//    public static ITransport Create(string type)
+//    {
+//        switch (type)
+//        {
+//            case "Air":
+//                {
+//                    var factory = new AirFactory();
+//                    return factory.CreateInstance();
+//                }
+//            case "Train":
+//                {
+//                    var factory = new TrainFactory();
+//                    return factory.CreateInstance();
+//                }
+
+//            case "Truck":
+//                {
+//                    return new TruckAdapter();
+//                }
+//            default:
+//                throw new NotImplementedException();
+//        }
+//    }
+//}
+
+//public interface ITransport
+//{
+//    void Send();
+//}
+
+//public class Air : ITransport
+//{
+//    public void Send()
+//    {
+//        Console.WriteLine("Send package by air ...");
+//    }
+//}
+
+//public class Train : ITransport
+//{
+//    public void Send()
+//    {
+//        Console.WriteLine("Send package by Train ...");
+//    }
+//}
+
+//public class TruckAdapter : ITransport
+//{
+//    private readonly Truck _truck;
+
+//    public TruckAdapter()
+//    {
+//        _truck = new Truck(5, "THR");
+//    }
+
+//    public void Send()
+//    {
+//        // Delegate the call to the Truck class's Deliver method
+//        // string -> xml nodes
+//        // <xml>
+//        // <node>............</node>
+//        //</xml>
+//        _truck.Deliver();
+//    }
+//}
+
+//public interface ITransportFactory
+//{
+//    ITransport CreateInstance();
+//}
+
+//public class AirFactory : ITransportFactory
+//{
+//    public ITransport CreateInstance()
+//    {
+//        //manage instance
+//        return new Air();
+//    }
+//}
+
+//public class TrainFactory : ITransportFactory
+//{
+//    public ITransport CreateInstance()
+//    {
+//        //manage instance
+//        return new Train();
+//    }
+//}
+
+//#endregion
+#region 1.9
+
+using CryptoCurrencyExternalLibrary;
 
-using ExternalClassLibrary;
 
 public class Program
 {
     public static void Main()
     {
         var type = Console.ReadLine();
-        ITransport transport = TransportService.Create(type);
-        transport.Send();
+        Console.WriteLine("Please enter the amount:");
+
+        string input = Console.ReadLine();
+        if (decimal.TryParse(input, out decimal amount))
+        {
+            Console.WriteLine($"The entered amount is: {amount}"); // You can now use the 'amount' variable as needed
+
+        }
+        else
+        {
+            Console.WriteLine("Invalid input, please enter a valid decimal number.");
+        }
+
+
+        IPayment payment = PaymentService.Create(type);
+        payment.ProcessPayment(amount);
+        amount = payment.AdjustAmount(amount);
     }
 }
 
-public class TransportService
+public class PaymentService
 {
-    public static ITransport Create(string type)
+    public static IPayment Create(string type)
     {
         switch (type)
         {
-            case "Air":
+            case "CreditCard":
                 {
-                    var factory = new AirFactory();
+                    var factory = new CreditCardFactory();
                     return factory.CreateInstance();
                 }
-            case "Train":
+            case "PayPal":
                 {
-                    var factory = new TrainFactory();
+                    var factory = new PayPalFactory();
                     return factory.CreateInstance();
                 }
 
-            case "Truck":
+            case "CryptoCurrency":
                 {
-                    return new TruckAdapter();
+                    return new CryptoCurrencyAdapter();
                 }
             default:
-                throw new NotImplementedException();
+                {
+                    var factory = new NullPaymentFactory();
+                    return factory.CreateInstance();
+                }
         }
     }
 }
 
-public interface ITransport
+public interface IPayment
 {
-    void Send();
-}
+    void ProcessPayment(decimal amount);
+    decimal AdjustAmount(decimal amount);
 
-public class Air : ITransport
+}
+public class CreditCard : IPayment
 {
-    public void Send()
+    private const decimal FeeRate = 0.02m;
+    public void ProcessPayment(decimal amount)
     {
-        Console.WriteLine("Send package by air ...");
+
+    }
+    public decimal AdjustAmount(decimal amount)
+    {
+        return amount + (amount * FeeRate);
     }
+
 }
 
-public class Train : ITransport
+public class PayPal : IPayment
 {
-    public void Send()
+    private const decimal DiscountRate = 0.03m;
+    public void ProcessPayment(decimal amount)
     {
-        Console.WriteLine("Send package by Train ...");
+        Console.WriteLine();
+    }
+    public decimal AdjustAmount(decimal amount)
+    {
+        return amount - (amount * DiscountRate);
     }
 }
 
-public class TruckAdapter : ITransport
+public class CryptoCurrencyAdapter : IPayment
 {
-    private readonly Truck _truck;
+    private readonly CryptoCurrency _cryptoCurrency;
 
-    public TruckAdapter()
+    public CryptoCurrencyAdapter()
     {
-        _truck = new Truck(5,"THR");
+        _cryptoCurrency = new CryptoCurrency();
     }
 
-    public void Send()
+    public decimal AdjustAmount(decimal amount)
     {
-        // Delegate the call to the Truck class's Deliver method
-        // string -> xml nodes
-        // <xml>
-        // <node>............</node>
-        //</xml>
-        _truck.Deliver();
+        return _cryptoCurrency.ExternalProcessPayment(amount);
     }
+
+    public void ProcessPayment(decimal amount)
+    {
+        throw new NotImplementedException();
+    }
+}
+
+public interface IPaymentFactory
+{
+    IPayment CreateInstance();
 }
 
-public interface ITransportFactory
+public class CreditCardFactory : IPaymentFactory
 {
-    ITransport CreateInstance();
+    public IPayment CreateInstance()
+    {
+        //manage instance
+        return new CreditCard();
+    }
 }
 
-public class AirFactory : ITransportFactory
+public class PayPalFactory : IPaymentFactory
 {
-    public ITransport CreateInstance()
+    public IPayment CreateInstance()
     {
         //manage instance
-        return new Air();
+        return new PayPal();
     }
 }
 
-public class TrainFactory : ITransportFactory
+public class NullPayment : IPayment
+{
+    public decimal AdjustAmount(decimal amount)
+    {
+        return amount;
+    }
+
+    public void ProcessPayment(decimal amount)
+    {
+        Console.WriteLine($"Payment method not supported. Unable to process ${amount:F2}.");
+    }
+
+}
+public class NullPaymentFactory : IPaymentFactory
 {
-    public ITransport CreateInstance()
+    public IPayment CreateInstance()
     {
         //manage instance
-        return new Train();
+        return new NullPayment();
     }
 }
 
+
 #endregion
\ No newline at end of file