diff -r c6f975266155 -r ddcb616e036a cws/cw02.tex
--- a/cws/cw02.tex	Thu Oct 29 00:11:32 2020 +0000
+++ b/cws/cw02.tex	Thu Oct 29 00:25:20 2020 +0000
@@ -76,6 +76,8 @@
   \texttt{,} and
   \texttt{:}
 
+  \textcolor{red}{Please also add \texttt{$\backslash$} for the collatz program.}
+
 \item strings are enclosed by \texttt{"\ldots"} and consisting of
   symbols, whitespaces and digits
 \item parentheses are \texttt{(}, \texttt{\{}, \texttt{)} and \texttt{\}}