3. (5 points) Find the determinant of the matrix

$A = \begin{bmatrix} 1 & 0 & 2 & 0 & 0 & 4 \\ 30 & 1 & 5 & 0 & 0 & 9 \\ 3 & 5 & 3 & 8 & 0 & 4 \\ 2 & 0 & 8 & 0 & 0 & 7 \\ 7 & 0 & 4 & 0 & 6 & 0 \\ 0 & 0 & 1 & 0 & 2 & 0 \end{bmatrix}.$