diff --git a/15-more-types/mysum.py b/15-more-types/mysum.py
index 2c341aa..6215bdd 100644
--- a/15-more-types/mysum.py
+++ b/15-more-types/mysum.py
@@ -1,7 +1,6 @@
 import functools
 import operator
-from collections.abc import Iterable
-from typing import overload, Union, TypeVar
+from typing import overload, Union, TypeVar, Iterable
 
 T = TypeVar('T')
 S = TypeVar('S')  # <1>