Here's another problem, significantly harder than the first, but still accessible to target audience. The statement of the problem (i.e., northwest corner only) comes from a PennyDell puzzle magazine:
EDIT The problem is described below in the comments; additionally, NTRF is N times OGRE and ONOT is SLOG minus NTRF; the "A" is "brought down" per algorithm. Next two hunks explained similarly.
