length of $\mathbb{C}[x]/(x^{50}+x+1)\mathbb{C}[x]$ as a $\mathbb{C}[x]$-module

Question

I was wondering how to compute the length of $\mathbb{C}[x]/(x^{50}+x+1)\mathbb{C}[x]$ as an $\mathbb{C}[x]$-module or how to proceed in general when you have such a large quotient, as you can´t just wirte down a decompositionseries. I know that the maximal Ideals of $\mathbb{C}[x]$ are of the form $(x-a)$ with $a\in\mathbb{C}$, but im a bit confused how to compute the length now.