diff --git a/d00/ex04/whatis.py b/d00/ex04/whatis.py
index ffb6ac5..bf7a511 100644
--- a/d00/ex04/whatis.py
+++ b/d00/ex04/whatis.py
@@ -6,6 +6,7 @@ def check_parity(args: list[str]):
         return
 
     arg = args[0]
+    # https://docs.python.org/3.10/tutorial/errors.html
     try:
         number = int(arg)
     except ValueError: