diff --git a/src/Lib.hs b/src/Lib.hs
index 3387a8d2094c003dbced7e789daeae8d8ad7ccd7..7e32b670d15ce091fc396b66de1c32d37fcd8ea8 100755
--- a/src/Lib.hs
+++ b/src/Lib.hs
@@ -19,3 +19,5 @@ handler person context =
     return (Right person)
   else
     return (Left "A person's age must be positive")
+
+countNB a b = zipWith (+) a b