Question
In the group $(\mathbb{Z}, *)$, if $a * b = a + b - n$ for all $a, b \in \mathbb{Z}$, where $n$ is a fixed integer, then the inverse of $-n$ is _____.
In the group $(\mathbb{Z}, *)$, if $a * b = a + b - n$ for all $a, b \in \mathbb{Z}$, where $n$ is a fixed integer, then the inverse of $-n$ is _____.