Matrices & Systems · Medium problem

Let $A = \begin{pmatrix}0 & -1 & 1 \\ 0 & 3 & 0\end{pmatrix}$ and $B = \begin{pmatrix}1 & 4 \\ -2 & -1 \\ 0 & -3\end{pmatrix}$. Find the entry in row $1$, column $1$ of $AB$.