\begin{equation*} \Z\setminus\overline{B} =\left(\bigcup_{\substack{n\in\Z\\n\text{ ganjil}}}\{n\}\right) \cup \left(\bigcup_{\substack{n\in\Z\setminus\{0\}\\n\text{ genap}}}B(n)\right) \end{equation*}