diff --git a/src/main/java/hse/java/lectures/lecture6/tasks/queue/BoundedBlockingQueue.java b/src/main/java/hse/java/lectures/lecture6/tasks/queue/BoundedBlockingQueue.java
index 5c686cff..ec9c56d6 100644
--- a/src/main/java/hse/java/lectures/lecture6/tasks/queue/BoundedBlockingQueue.java
+++ b/src/main/java/hse/java/lectures/lecture6/tasks/queue/BoundedBlockingQueue.java
@@ -1,25 +1,25 @@
-package hse.java.lectures.lecture6.tasks.queue;
-
-public class BoundedBlockingQueue<T> {
-
-
-    public BoundedBlockingQueue(int capacity) {
-
-    }
-
-    public void put(T item) {
-
-    }
-
-    public T take() {
-        return null;
-    }
-
-    public int size() {
-        return 0;
-    }
-
-    public int capacity() {
-        return 0;
-    }
-}
+package hse.java.lectures.lecture6.tasks.queue;
+
+public class BoundedBlockingQueue<T> {
+
+
+    public BoundedBlockingQueue(int capacity) {
+
+    }
+
+    public void put(T item) throws InterruptedException {
+
+    }
+
+    public T take() throws InterruptedException {
+        return null;
+    }
+
+    public int size() {
+        return 0;
+    }
+
+    public int capacity() {
+        return 0;
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/hse/java/lectures/lecture6/tasks/synchronizer/StreamWriter.java b/src/main/java/hse/java/lectures/lecture6/tasks/synchronizer/StreamWriter.java
index fedb5e66..d52a0c57 100644
--- a/src/main/java/hse/java/lectures/lecture6/tasks/synchronizer/StreamWriter.java
+++ b/src/main/java/hse/java/lectures/lecture6/tasks/synchronizer/StreamWriter.java
@@ -28,8 +28,22 @@ public void attachMonitor(StreamingMonitor monitor) {
     public void run() {
         // Writer threads are intentionally infinite for the task contract.
         while (true) {
-            output.print(message);
-            onTick.run();
+            synchronized (monitor) {
+                while (id != monitor.streamIds.get(monitor.nowIdIndex)) {
+                    try {
+                        monitor.wait();
+                    } catch (InterruptedException e) {
+                        throw new RuntimeException(e);
+                    }
+                }
+                if (monitor.cntTicks == monitor.cntCompleteTicks){
+                    break;
+                }
+                output.print(message);
+                onTick.run();
+                monitor.nextId();
+                monitor.notifyAll();
+            }
         }
     }
 
diff --git a/src/main/java/hse/java/lectures/lecture6/tasks/synchronizer/StreamingMonitor.java b/src/main/java/hse/java/lectures/lecture6/tasks/synchronizer/StreamingMonitor.java
index 68e8f279..d6c7da95 100644
--- a/src/main/java/hse/java/lectures/lecture6/tasks/synchronizer/StreamingMonitor.java
+++ b/src/main/java/hse/java/lectures/lecture6/tasks/synchronizer/StreamingMonitor.java
@@ -1,5 +1,28 @@
 package hse.java.lectures.lecture6.tasks.synchronizer;
 
+import java.util.List;
+import java.util.stream.Collectors;
+
 public class StreamingMonitor {
-    // impl your sync here
+    public int nowIdIndex = 0;
+    public int cntTicks;
+    public int cntCompleteTicks = 0;
+    public List<Integer> streamIds;
+
+    StreamingMonitor(List<StreamWriter> streamIds, int cntTicks) {
+        this.cntTicks = cntTicks;
+        this.streamIds = streamIds
+                .stream()
+                .map(writer -> writer.getId())
+                .sorted()
+                .collect(Collectors.toList());
+    }
+
+    void nextId() {
+        nowIdIndex++;
+        if (nowIdIndex == streamIds.size()) {
+            cntCompleteTicks++;
+            nowIdIndex = 0;
+        }
+    }
 }
diff --git a/src/main/java/hse/java/lectures/lecture6/tasks/synchronizer/Synchronizer.java b/src/main/java/hse/java/lectures/lecture6/tasks/synchronizer/Synchronizer.java
index 3cb8aded..78e4e980 100644
--- a/src/main/java/hse/java/lectures/lecture6/tasks/synchronizer/Synchronizer.java
+++ b/src/main/java/hse/java/lectures/lecture6/tasks/synchronizer/Synchronizer.java
@@ -7,27 +7,35 @@ public class Synchronizer {
     public static final int DEFAULT_TICKS_PER_WRITER = 10;
     private final List<StreamWriter> tasks;
     private final int ticksPerWriter;
+    private StreamingMonitor monitor;
 
     public Synchronizer(List<StreamWriter> tasks) {
         this(tasks, DEFAULT_TICKS_PER_WRITER);
+        monitor = new StreamingMonitor(tasks, DEFAULT_TICKS_PER_WRITER);
     }
 
     public Synchronizer(List<StreamWriter> tasks, int ticksPerWriter) {
         this.tasks = tasks;
         this.ticksPerWriter = ticksPerWriter;
+        monitor = new StreamingMonitor(tasks, ticksPerWriter);
     }
 
     /**
      * Starts infinite writer threads and waits until each writer prints exactly ticksPerWriter ticks
      * in strict ascending id order.
      */
-    public void execute() {
-        // add monitor and sync
+    public void execute() throws InterruptedException {
         for (StreamWriter writer : tasks) {
+            writer.attachMonitor(monitor);
             Thread worker = new Thread(writer, "stream-writer-" + writer.getId());
             worker.setDaemon(true);
             worker.start();
         }
+        synchronized (monitor) {
+            while (monitor.cntTicks  != monitor.cntCompleteTicks) {
+                monitor.wait();
+            }
+        }
     }
 
 }