diff --git a/2019/ruby/computer.rb b/2019/ruby/computer.rb
index a5bc7ca..9c0e7ac 100644
--- a/2019/ruby/computer.rb
+++ b/2019/ruby/computer.rb
@@ -148,3 +148,7 @@ class Computer
     end
   end
 end
+
+if __FILE__ == $0
+  Computer.from(T.cast(ARGF, IO).read || "").run
+end