$=\left[\begin{array}{lll}0 & 0 & 1 \\1 & 0 & 0 \\0 & 1 & 0\end{array}\right]$
$a \leftrightarrow R _{2}$
$-\left[\begin{array}{ccc}1 & 0 & 0 \\ 0 & 0 & 1 \\ 0 & 1 & 0\end{array}\right]$
$R _{2} \leftrightarrow R _{3}$
${\left[\begin{array}{lll}1 & 0 & 0 \\ 0 & 1 & 0 \\ 0 & 0 & 1\end{array}\right]=I }$
$B_{0}= A ^{49}+2 A ^{98}$
$= A +2 I$
$B _{ n }= Adj \left( B _{ n }-1\right)$
$=\operatorname{Adj}\left(\operatorname{Adj}\left(\operatorname{Adj}\left(\operatorname{Adj} B _{0}\right)\right)\right.$
$=\left| B _{0}\right|( n -1)^{4}$
$=\left| B _{0}\right|^{16}$
$B_{0}=\left[\begin{array}{lll}0 & 1 & 0 \\ 0 & 0 & 1 \\ 1 & 0 & 0\end{array}\right]+\left[\begin{array}{lll}2 & 0 & 0 \\ 0 & 2 & 0 \\ 0 & 0 & 2\end{array}\right]$
$=\left[\begin{array}{lll}2 & 1 & 0 \\ 0 & 2 & 1 \\ 1 & 0 & 2\end{array}\right]$
$=2(4-0)-1(0-1)$
$=9$
$B _{4}(9)^{16}=(3)^{32}$