$\begin{align}  & \,\,\,F\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,8 \\  & \,\,\,\,\downarrow \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\downarrow  \\  & \underbrace{1111}_{\underset{3}{\mathop{\downarrow }}\,}\,\,\,\,\,\,\underset{{}}{\mathop{\underbrace{{}}_{\underset{3}{\mathop{\downarrow }}\,}}}\,\,\,\,\,\,\,\,\underset{{}}{\mathop{\underbrace{1000}_{\underset{3}{\mathop{\downarrow }}\,}}}\, \\ \end{align}$