diff --git a/exam/ex.tex b/exam/ex.tex
index c84a2a5..3c543f5 100644
--- a/exam/ex.tex
+++ b/exam/ex.tex
@@ -68,7 +68,10 @@
       operates on fixed-length inputs. Messages come in variable-length sizes
       and need to be padded by the block cipher to the specified block size.
 
-    \item \TODO
+    \item Depending on the amount of input blocks, the construction will
+      generate multiples of the block size as outputs. The outputs are
+      variable-length.
+
     \item \TODO
     \item \TODO
     \item \TODO