16. Find the product $A B$, if

$$
A=\left(\begin{array}{rrr}
0 & -1 & 2 \\
2 & 1 & 1 \\
3 & 0 & 1 \\
3 & 7 & 1
\end{array}\right), \quad B=\left(\begin{array}{ll}
3 & 1 \\
2 & 1 \\
1 & 0
\end{array}\right)
$$