diff --git a/Main.java b/Main.java
index 1a68b2dd0a36d3447eed91dc217b0ec3bb12c172..2cff7ed2e0f9559eb9caceecea17a83d94529787 100644
--- a/Main.java
+++ b/Main.java
@@ -1,5 +1,36 @@
-class Main {
-  public static void main(String[] args) {
-    System.out.println("Hello world!");
-  }
+import java.util.LinkedList;
+import java.util.List;
+import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.concurrent.Semaphore;
+
+public class Main {
+    private static final List<Integer> productCodeDetailsList = new CopyOnWriteArrayList<>();
+    private static final Semaphore semaphore = new Semaphore(1);
+
+    public static void main(String[] args) {
+        for (int i = 0; i < 1000; i++) {
+            int finalI = i;
+            new Thread(() -> {
+                try {
+                    semaphore.acquire();
+                    productCodeDetailsList.add(finalI);
+                    if (finalI % 100 == 0) {
+                        productCodeDetailsList.clear();
+                    }
+                } catch (InterruptedException e) {
+                    e.printStackTrace();
+                } finally {
+                    semaphore.release();
+                }
+            }).start();
+        }
+
+        try {
+            Thread.sleep(3000);
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+        System.out.println(productCodeDetailsList);
+        System.out.println(productCodeDetailsList.size());
+    }
 }
\ No newline at end of file