diff --git a/dynamic_programming/iterating_through_submasks.py b/dynamic_programming/iterating_through_submasks.py
index d855dbe47..f33052b28 100644
--- a/dynamic_programming/iterating_through_submasks.py
+++ b/dynamic_programming/iterating_through_submasks.py
@@ -35,7 +35,7 @@ def list_of_submasks(mask) -> list:
     
     """
 
-    fmt = "n needs to be positive integer, your input {}"
+    fmt = "mask needs to be positive integer, your input {}"
     assert isinstance(mask, int) and mask > 0, fmt.format(mask)
 
     """