Fix typo.

Thou shalt not count to two unless proceeding to the number three.
diff --git a/Doc/tut/tut.tex b/Doc/tut/tut.tex
index 947bfe5..9b8d0ba 100644
--- a/Doc/tut/tut.tex
+++ b/Doc/tut/tut.tex
@@ -199,7 +199,7 @@
 a file as standard input, it reads and executes a \emph{script} from
 that file. 
 
-A third way of starting the interpreter is
+A second way of starting the interpreter is
 \samp{\program{python} \programopt{-c} \var{command} [arg] ...}, which
 executes the statement(s) in \var{command}, analogous to the shell's
 \programopt{-c} option.  Since Python statements often contain spaces