Input (grade 5): The initial releases were successively numbered as "previews" i.e. p5, p7, p8 up to p81a, then p9, p91, p92, and p93.
Output (grade 5): The initial releases were successively numbered as "previews" i.e. p5, p7, p8 up to p81a, then p9, p91, p92.