diff --git a/lectures b/lectures
index 97c198a..f9ffdf7 160000
--- a/lectures
+++ b/lectures
@@ -1 +1 @@
-Subproject commit 97c198a084ef1a9595b62de34bc55926739f8bda
+Subproject commit f9ffdf7e0fed0d6abbfc468de4f58f7efe2cd7f1