\[\boxed{\mathbf{217}\mathbf{.}}\]
\[BD = 12\ см;\ \]
\[CE = 16\ см;\]
\[CD = 5\ см;\]
\[DE = CE - CD = 16 - 5 =\]
\[= 11\ см.\]
\[BE = BD + DE = 12 + 11 =\]
\[= 23\ см.\]
\[Ответ:23\ см.\]