Let $A = \begin{pmatrix} a_{ij} \end{pmatrix}_{2 \times 2} = \begin{pmatrix} \log_{5} 128 & \log_{5} 8 \\ \log_{4} 25 & \log_{4} 5 \end{pmatrix}$. If $A_{ij}$ is the cofactor of $a_{ij}$, $C_{ij} = \sum_{k} a_{ik} A_{jk}, \; 1 \le i, j \le 2$, and $C = [C_{ij}]$, then $8|C|$ is equal to: