$${\mathtt{\,-\,}}{\mathtt{11}}{\mathtt{\,\small\textbf+\,}}\left({\mathtt{12}}\right){\mathtt{\,\small\textbf+\,}}\left({\mathtt{15}}\right) = {\mathtt{16}}$$
.$${\mathtt{\,-\,}}{\mathtt{11}}{\mathtt{\,\small\textbf+\,}}\left({\mathtt{12}}\right){\mathtt{\,\small\textbf+\,}}\left({\mathtt{15}}\right) = {\mathtt{16}}$$