diff --git a/src/L28.java b/src/L28.java
new file mode 100644
index 0000000..7951119
--- /dev/null
+++ b/src/L28.java
@@ -0,0 +1,23 @@
+import utils.Queue;
+
+public class L28 extends Main {
+
+    public static int sumH(Queue<Integer> queue) {
+        int x = queue.remove();
+        if (queue.head() > x) {
+            queue.insert(x);
+            return queue.head() - x + sumH(queue);
+        } else {
+             queue.insert(x);
+             return 0;
+        }
+    }
+
+    public static void main(String[] args) {
+        Queue<Integer> queue = buildQueue(1,4,8,17,20);
+        System.out.println(queue);
+        System.out.println(sumH(queue));
+        System.out.println(queue);
+    }
+
+}
diff --git a/src/utils/HelpCommands.java b/src/utils/HelpCommands.java
index 1440b72..b1c28a2 100644
--- a/src/utils/HelpCommands.java
+++ b/src/utils/HelpCommands.java
@@ -285,6 +285,14 @@ public static Queue<Integer> buildQueue(int n, int max) {
         return queue;
     }
 
+    public static Queue<Integer> buildQueue(int... values) {
+        Queue<Integer> queue = new Queue<>();
+        for (int value : values) {
+            queue.insert(value);
+        }
+        return queue;
+    }
+
     /**
      * @param queue
      * @return the length of the queue