diff --git a/scala_project_2025/part1/src/main/scala/Main.scala b/scala_project_2025/part1/src/main/scala/Main.scala
index 7096b9d..e7ecc00 100644
--- a/scala_project_2025/part1/src/main/scala/Main.scala
+++ b/scala_project_2025/part1/src/main/scala/Main.scala
@@ -43,3 +43,7 @@ def quadratic(a: Double, b: Double, c: Double): Option[(Double, Double)] =
 // task 2 a)
 def polynomial(a: Double, b: Double, c: Double): Double => Double =
   (x: Double) => a * x * x + b * x + c
+
+// task 3 a)
+def initialize_thread(execute: () => Unit): Thread =
+  new Thread { override def run = execute() }
diff --git a/scala_project_2025/part1/src/main/scala/conc/ConcurrencyTroubles.scala b/scala_project_2025/part1/src/main/scala/conc/ConcurrencyTroubles.scala
new file mode 100644
index 0000000..7d2de37
--- /dev/null
+++ b/scala_project_2025/part1/src/main/scala/conc/ConcurrencyTroubles.scala
@@ -0,0 +1,52 @@
+package example
+
+import scala.concurrent.Future
+import scala.concurrent.ExecutionContext.Implicits.global
+import scala.concurrent.Await
+import scala.concurrent.duration.Duration
+
+object ConcurrencyTroubles {
+  private var value1: Int = 1000
+  private var value2: Int = 0
+  private var sum: Int = 0
+
+  def moveOneUnit(): Unit = {
+    value1 -= 1
+    value2 += 1
+    if (value1 == 0) {
+      value1 = 1000
+      value2 = 0
+    }
+  }
+
+  def updateSum(): Unit = {
+    sum = value1 + value2
+  }
+
+  def execute(): Unit = {
+    while (true) {
+      this.synchronized {
+        moveOneUnit()
+        updateSum()
+      }
+      Thread.sleep(50)
+    }
+  }
+
+  // This is the "main" method, the entry point of execution.
+  // It could have been placed in a different file.
+  def main(args: Array[String]): Unit = {
+    for (i <- 1 to 2) {
+      val thread = new Thread {
+        override def run = execute()
+      }
+      thread.start()
+    }
+
+    while (true) {
+      updateSum()
+      println(sum + " [" + value1 + " " + value2 + "]")
+      Thread.sleep(100)
+    }
+  }
+}