diff --git a/adder/__init__.py b/adder/__init__.py
index aa1c3a2..07b9924 100644
--- a/adder/__init__.py
+++ b/adder/__init__.py
@@ -4,5 +4,5 @@
 from numpy import array
 
 def run(*args):
-    return -1*array(args).sum()
+    return array(args).sum()