<s>[INST] Let $x = \frac{1}{2}\sqrt[3]{\frac{a}{b}-1} - 1$ and $y = 2\sqrt[3]{b^2a - 1}$, where $a$ and $b$ are integers. Given that $x + y$ is also an integer, what is the value of $(2a + 1)(2b + 1)(x + y + 2)$?[/INST]