diff --git a/src/Lib.hs b/src/Lib.hs
index 7e32b670d15ce091fc396b66de1c32d37fcd8ea8..8419187fda65f84358c05d2ee978562ff52a5643 100755
--- a/src/Lib.hs
+++ b/src/Lib.hs
@@ -21,3 +21,6 @@ handler person context =
     return (Left "A person's age must be positive")
 
 countNB a b = zipWith (+) a b
+
+power n 1 = n
+power n m = n * (power n (m-1))