sentences: (b) Notwithstanding subsection (a) of this section, in the case of any alien described in such subsection—
  (1) whose deportation was subsequent to a conviction for commission of [certain misdemeanors] or a felony [other than an aggravated felony], such alien shall be fined under title 18, or imprisoned not more than 10 years or both, or
  (2) whose deportation was subsequent to a conviction for an aggravated felony, such alien shall be fined under title 18, imprisoned not more than 20 years, or both.The Court had to decide whether subsection (b)(2), the provision that allowed the district court to impose the 85-month sentence in this case, was a separate crime or merely a penalty provision.