diff --git a/04/src/main/java/ch/zhaw/ads/HanoiServer.java b/04/src/main/java/ch/zhaw/ads/HanoiServer.java
new file mode 100644
index 0000000..c3c23e7
--- /dev/null
+++ b/04/src/main/java/ch/zhaw/ads/HanoiServer.java
@@ -0,0 +1,23 @@
+package ch.zhaw.ads;
+
+public class HanoiServer implements CommandExecutor {
+
+    @Override
+    public String execute(String command) {
+        int n = Integer.parseInt(command);
+        return moveDisk(n, 'A', 'B', 'C');
+    }
+
+    public String moveDisk(int n, char from, char to, char help) {
+        String out = "";
+        if (n > 0) {
+            // bewege Stapel n-1 von from auf help
+            out += moveDisk(n-1, from, help, to);
+            // bewege von from nach to
+            out += "move " + from + " to " + to + "\n";
+            // bewege Stapel n-1 von help auf to
+            out += moveDisk(n-1, help, to, from);
+        }
+        return out;
+    }
+}