The components of pure shear strain in a sheared material are given in the matrix form:
$$ \varepsilon = \begin{bmatrix} 1 & 1 \\ 1 & – 1 \end{bmatrix}$$
Here, $\text{Trace}(\varepsilon) = 0.$ Given, $ P = \text{Trace}(\varepsilon^{8})$ and $Q = \text{Trace}(\varepsilon^{11}).$
The numerical value of $(P + Q)$ is _____________. (in integer)