Fix typo spotted by Sandro Tosi
diff --git a/Doc/tutorial/classes.rst b/Doc/tutorial/classes.rst
index bdaa5d2..ed0e655 100644
--- a/Doc/tutorial/classes.rst
+++ b/Doc/tutorial/classes.rst
@@ -518,7 +518,7 @@
than the super call found in single-inheritance languages.
With new-style classes, dynamic ordering is necessary because all cases of
-multiple inheritance exhibit one or more diamond relationships (where one at
+multiple inheritance exhibit one or more diamond relationships (where at
least one of the parent classes can be accessed through multiple paths from the
bottommost class). For example, all new-style classes inherit from
:class:`object`, so any case of multiple inheritance provides more than one path