SASMO 2020 Grade 8 Question 7

The value of $\dfrac{2022^3-2\times2022^2-2020}{2021^3+2\times2021^2-2023}$ is $\dfrac ab$, where $\operatorname{HCF}(a,b)=1$. Find $a+b$. Take $a,b$ to be positive integers.