This is a follow up to an earlier question What is the etale fundamental group of Spec Z((x))?

This is a follow up to an earlier question What is the etale fundamental group of Spec Z((x))?

Question 4: What are the residue field $\ZZ((x))/f(x)$, where $f(x) = p^n + a_1x + a_2x^2 + \cdots$? (assuming $f$ is irreducible)

Question 4: What are the residue fields of the form $\ZZ((x))/f(x)$, where $f(x) = p^n + a_1x + a_2x^2 + \cdots$? (assuming $f$ is irreducible and $p\nmid f$)