diff --git a/src/main/java/lesson_11_04_2018/BlockingStack.java b/src/main/java/lesson_11_04_2018/BlockingStack.java
index 95d581e..11adf12 100644
--- a/src/main/java/lesson_11_04_2018/BlockingStack.java
+++ b/src/main/java/lesson_11_04_2018/BlockingStack.java
@@ -17,6 +17,9 @@
 // ______
 
 
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
 import java.util.concurrent.locks.Condition;
 import java.util.concurrent.locks.Lock;
 import java.util.concurrent.locks.ReentrantLock;
@@ -24,7 +27,7 @@
 public class BlockingStack<T> {
 
     private final Object[] arr;
-    private int current = 0;
+    private volatile int current = 0;
     private final Lock lock = new ReentrantLock();
     private final Condition notEmpty = lock.newCondition();
     private final Condition notFull = lock.newCondition();
@@ -33,14 +36,63 @@ public BlockingStack(int size) {
         arr = new Object[size];
     }
 
-    public void push(T element) {
-        // TODO
+    public void push(T element) throws InterruptedException {
+
+        lock.lock();
+        while (current > arr.length - 1) notFull.await();
+        try {
+
+            System.out.printf("trying push... %s/%s\n", current, arr.length-1);
+            arr[current++] = element;
+        } finally {
+            notEmpty.signal();
+            lock.unlock();
+        }
     }
 
     @SuppressWarnings("unchecked")
-    public T pop() {
-        // TODO
-        return (T) arr[current];
+    public T pop() throws InterruptedException {
+        lock.lock();
+        while (current == 0) notEmpty.await();
+        try {
+            System.out.printf("trying pop... %s/%s\n", current - 1, arr.length-1 );
+            return (T) arr[--current];
+        } finally {
+            notFull.signal();
+            lock.unlock();
+        }
+    }
+
+}
+
+class TestBlockingStack {
+    public static void main(String[] args) {
+        BlockingStack<Integer> integerBlockingStack = new BlockingStack<>(5);
+
+        ExecutorService service = Executors.newCachedThreadPool();
+
+        service.submit(() -> {
+            int count=0;
+
+            while (true) {
+                integerBlockingStack.push(count++);
+            }
+
+
+        });
+        service.submit(() -> {
+            while (true) {
+                try {
+                    TimeUnit.SECONDS.sleep(2);
+                    integerBlockingStack.pop();
+
+                } catch (InterruptedException e) {
+                    e.printStackTrace();
+                }
+            }
+        });
+
+        service.shutdown();
     }
 
 }