diff --git a/p20/p20.org b/p20/p20.org
index 635635c..95b64e6 100644
--- a/p20/p20.org
+++ b/p20/p20.org
@@ -73,8 +73,9 @@ Now look for gaps:
 : 1426
 
 Alternatively, collect all element of the path that are –in the
-taxicab distance– closer than 20 to any given element of the path;
-then compute the time saved by using the cheat
+taxicab distance– closer than 20 to any given element of the path,
+then compute the time saved by using the cheat and filter only those
+that save at least 100 picoseconds
 #+begin_src emacs-lisp
   (length
    (--filter (>= it 100)