diff --git a/app.js b/app.js
new file mode 100644
index 0000000..c9a9ea3
--- /dev/null
+++ b/app.js
@@ -0,0 +1,8 @@
+const n = 4;
+let sum = 0;
+
+for (let i = 1; i <= n; i++) {
+    sum += i;
+}
+
+console.log(sum);
\ No newline at end of file
diff --git a/index.html b/index.html
index b8974cf..056c6e3 100644
--- a/index.html
+++ b/index.html
@@ -4,8 +4,9 @@
     <meta charset="UTF-8">
     <meta name="viewport" content="width=h1, initial-scale=1.0">
     <title>Document</title>
+    <script src="app.js"></script>
 </head>
 <body>
-    <h1>Hello world!</h1>
+    <h1>Loop under the Hood</h1>
 </body>
 </html>
\ No newline at end of file
