diff --git a/src/teaching/cse-250/2022fa/index.erb b/src/teaching/cse-250/2022fa/index.erb
index 485e2896..2367604f 100644
--- a/src/teaching/cse-250/2022fa/index.erb
+++ b/src/teaching/cse-250/2022fa/index.erb
@@ -285,6 +285,8 @@ schedule:
     - date: 09/26/22
       topic: Recursive Analysis; Sorts
       dow: Mon
+      section_a:
+        slides: slide/lec12a.pdf
       section_b:
         slides: slide/11b-RecursionAnalysis.html
     - date: 09/28/22
diff --git a/src/teaching/cse-250/2022fa/slide/lec12a.pdf b/src/teaching/cse-250/2022fa/slide/lec12a.pdf
new file mode 100644
index 00000000..8f01a88c
Binary files /dev/null and b/src/teaching/cse-250/2022fa/slide/lec12a.pdf differ