diff --git a/merge-two-sorted-lists/nakjun12.ts b/merge-two-sorted-lists/nakjun12.ts
new file mode 100644
index 000000000..03fce8d74
--- /dev/null
+++ b/merge-two-sorted-lists/nakjun12.ts
@@ -0,0 +1,24 @@
+function mergeTwoLists(
+  list1: ListNode | null,
+  list2: ListNode | null
+): ListNode | null {
+  let head = new ListNode();
+  let current = head;
+
+  while (list1 && list2) {
+    if (list1.val <= list2.val) {
+      current.next = list1;
+      list1 = list1.next;
+    } else {
+      current.next = list2;
+      list2 = list2.next;
+    }
+    current = current.next;
+  }
+  current.next = list1 || list2;
+
+  return head.next;
+}
+
+// TC: O(m+n)
+// SC: O(1)