diff --git a/.devcontainer.json b/.devcontainer.json
new file mode 100644
index 0000000..bfbeb0d
--- /dev/null
+++ b/.devcontainer.json
@@ -0,0 +1,3 @@
+{
+    "image": "mcr.microsoft.com/devcontainers/java:21"
+}
\ No newline at end of file
diff --git a/.vscode/extensions.json b/.vscode/extensions.json
new file mode 100644
index 0000000..add4f4e
--- /dev/null
+++ b/.vscode/extensions.json
@@ -0,0 +1,5 @@
+{
+    "recommendations": [
+        "vscjava.vscode-java-pack"
+    ]
+}
\ No newline at end of file
diff --git a/Exercise.java b/Exercise.java
index 2d4d392..da365f3 100644
--- a/Exercise.java
+++ b/Exercise.java
@@ -1,7 +1,9 @@
 public class Exercise {
 
   public static void main(String[] args) {
+    TravelAgency travelAgency = new TravelAgency("Reisebuero Schmidt");
     Rental rental = new Rental("Fahrzeugvermietung Mueller");
+    travelAgency.addPartner(rental);
 
     Car car1 = new Car("Porsche", "911", Engine.ELECTRO, 2);
     Truck truck1 = new Truck("MAN", "TGX", Engine.DIESEL, 20);
@@ -21,6 +23,6 @@ public static void main(String[] args) {
     rental.addVehicle(truck1);
     rental.addVehicle(car2);
 
-    System.out.println(rental.toString());
+    System.out.println(travelAgency.toString());
   }
 }
diff --git a/Partner.java b/Partner.java
new file mode 100644
index 0000000..e2827f5
--- /dev/null
+++ b/Partner.java
@@ -0,0 +1,3 @@
+public interface Partner {
+  public String toString();
+}
diff --git a/Rental.java b/Rental.java
index 96033af..b8bcd7a 100644
--- a/Rental.java
+++ b/Rental.java
@@ -1,6 +1,6 @@
 import java.util.ArrayList;
 
-public class Rental {
+public class Rental implements Partner {
 
   private final String name;
   private final ArrayList<Vehicle> vehicles;
diff --git a/TravelAgency.java b/TravelAgency.java
new file mode 100644
index 0000000..3ac9f7d
--- /dev/null
+++ b/TravelAgency.java
@@ -0,0 +1,24 @@
+import java.util.ArrayList;
+
+public class TravelAgency {
+
+  private String name;
+  private ArrayList<Partner> partners;
+
+  public TravelAgency(String name) {
+    this.name = name;
+    partners = new ArrayList<>();
+  }
+
+  public void addPartner(Partner partner) {
+    partners.add(partner);
+  }
+
+  public String toString() {
+    String result = name + "\n";
+    for (Partner p : partners) {
+      result += p.toString() + '\n';
+    }
+    return result;
+  }
+}