def METHOD_NAME(self, n):
    """
    Return the quotient of the ring of integers by the `n`-th power of its maximal ideal.
    EXAMPLES::
        sage: S.<x> = ZZ[]
        sage: W.<w> = Zp(5).extension(x^2 - 5)
        sage: W.residue_ring(1)
        Ring of integers modulo 5
    The following requires implementing more general Artinian rings::
        sage: W.residue_ring(2)
        Traceback (most recent call last):
        ...
        NotImplementedError
    """
    if n == 1:
        return self.ground_ring().METHOD_NAME(1)
    else:
        raise NotImplementedError