diff --git a/src/exercicses/ex_a/HelloRunnable.java b/src/exercicses/ex_a/HelloRunnable.java
new file mode 100644
index 0000000..2d76be3
--- /dev/null
+++ b/src/exercicses/ex_a/HelloRunnable.java
@@ -0,0 +1,8 @@
+package exercicses.ex_a;
+
+public class HelloRunnable implements Runnable {
+    @Override
+    public void run() {
+        System.out.println("Hello from a class implementing the Runnable interface");
+    }
+}
diff --git a/src/exercicses/ex_a/HelloThread.java b/src/exercicses/ex_a/HelloThread.java
new file mode 100644
index 0000000..4aa5ad7
--- /dev/null
+++ b/src/exercicses/ex_a/HelloThread.java
@@ -0,0 +1,8 @@
+package exercicses.ex_a;
+
+public class HelloThread extends Thread {
+    @Override
+    public void run() {
+        System.out.println("Hello from a class extending the Thread class");
+    }
+}
diff --git a/src/exercicses/ex_a/TestingSimpleThreads.java b/src/exercicses/ex_a/TestingSimpleThreads.java
new file mode 100644
index 0000000..ac93172
--- /dev/null
+++ b/src/exercicses/ex_a/TestingSimpleThreads.java
@@ -0,0 +1,8 @@
+package exercicses.ex_a;
+
+public class TestingSimpleThreads {
+    public static void main(String[] args) {
+        new HelloThread().start();
+        new Thread(new HelloRunnable()).start();
+    }
+}