diff --git a/sik9252/MaximumDepthOfBinaryTree.js b/sik9252/MaximumDepthOfBinaryTree.js
new file mode 100644
index 0000000..ffdeb67
--- /dev/null
+++ b/sik9252/MaximumDepthOfBinaryTree.js
@@ -0,0 +1,12 @@
+/**
+ * @param {TreeNode} root
+ * @return {number}
+ */
+var maxDepth = function (root) {
+  if (!node) return 0;
+
+  const left = maxDepth(root.left);
+  const right = maxDepth(root.right);
+
+  return Math.max(left, right) + 1;
+};
diff --git a/sik9252/MiddleOfTheLinkedList.js b/sik9252/MiddleOfTheLinkedList.js
new file mode 100644
index 0000000..7598526
--- /dev/null
+++ b/sik9252/MiddleOfTheLinkedList.js
@@ -0,0 +1,15 @@
+/**
+ * @param {ListNode} head
+ * @return {ListNode}
+ */
+var middleNode = function (head) {
+  let slow = head;
+  let fast = head;
+
+  while (fast !== null && fast.next !== null) {
+    slow = slow.next;
+    fast = fast.next.next;
+  }
+
+  return slow;
+};