diff --git a/src/p53.k b/src/p53.k
index f630b94..b2a66ab 100644
--- a/src/p53.k
+++ b/src/p53.k
@@ -1,3 +1,3 @@
-fact:{*/1+!x}
+fact:*/1+!:
 choose:{(fact x)%(fact y)*fact x-y}
-+/{$[x>1000000;1;0]}',/{x choose'x-!x}'1+!100
++/1000000<,/{x choose'x-!x}'1+!100