Name c -> cls in example.
diff --git a/Doc/tutorial/classes.rst b/Doc/tutorial/classes.rst
index 576ef3a..a0f2431 100644
--- a/Doc/tutorial/classes.rst
+++ b/Doc/tutorial/classes.rst
@@ -673,9 +673,9 @@
    class D(C):
        pass
 
-   for c in [B, C, D]:
+   for cls in [B, C, D]:
        try:
-           raise c()
+           raise cls()
        except D:
            print("D")
        except C: