If $\int\limits_{ - a}^a {\left( {\left| x \right| + \left| {x - 2} \right|} \right)} dx = 22$, (a > 2) and [x] denotes the greatest integer $ \le $ x, then$\int\limits_{ - a}^a {\left( {x + \left[ x \right]} \right)} dx$ is equal to _________.