check number is not too big

diff --git a/ast b/ast
index 8464a8f3b73c022f8af4a0a317c3affddaf4fceb..d87fc045c20a0ae0eb83527b374eca08300f841b 160000 (submodule)
--- a/ast
+++ b/ast
@@ -1 +1 @@
-Subproject commit 8464a8f3b73c022f8af4a0a317c3affddaf4fceb
+Subproject commit d87fc045c20a0ae0eb83527b374eca08300f841b