If
\[
A = \begin{bmatrix}
\cos\theta & \sin\theta & 0
-\sin\theta & \cos\theta & 0
0 & 0 & 1
\end{bmatrix}
\]
and \( A_{11}, A_{12}, A_{13} \) are the cofactors of \( a_{11}, a_{12}, a_{13} \) respectively, then the value of \( a_{11} A_{11} + a_{12} A_{12} + a_{13} A_{13} \) is: