diff --git a/13_while_amount_of_numbers.py b/13_while_amount_of_numbers.py
index 83cccd4..be7eb08 100644
--- a/13_while_amount_of_numbers.py
+++ b/13_while_amount_of_numbers.py
@@ -6,7 +6,7 @@
 c = int (input())
 s = 0
 while c != 0:
-    s = s + c
+    s += c 
     c = int (input())
 print (s)