Solution to Problem 12: "Pentomino Paint by Numbers"

	We start off with the basic Paint by Numbers logic.  For instance, in the first column, no matter how the blocks are aligned, the sixth and seventh cells will be filled in, so the spots to the right of them will be blanks because their rows both start with a "1".  We can do more work in the fifth and seventh rows,   then in the second and fifth columns.  That gives us more information in the third row, which gives us more on the first row and finally the eighth row.
	The first column is obviously where the "I" pentomino is.   If the I pentomino stretched from rows 4-8 or from rows 6-10, then it would have to have more than five squares in it (because either the top or bottom row would contain 2 squares in addition to the five in the line).  Therefore, the I pentomino must run from rows 5-9. More standard Paint by Number analysis gets us up to the next diagram:
	We also know that no two pentominoes are diagonally adjacent, so the squares in the second column that are diagonally adjacent to the I pentomino must be blank.  Additional standard analysis gets us here:
	The bottom cell in the first column must be blank for the following reason.  If it were filled in, then the first four cells in the bottom row would be filled in.  The cells above them in the first, second, and fourth columns would be empty, but that violates the fact that the first group in the second row from the bottom has three squares in it. Since the bottom cell in the first column is blank, the one right above it must be filled, which leads to more information:
	The completed U and T pentominoes can have their diagonal elements blanked out as well, which leads us at once to the solution.
	We notice that the P and L pentominoes needed to be flipped from their displayed orientation to fit into the diagram, and that V, X, Y, and Z pentominoes were in their given orientation.  So the answer to submit is PL VXYZ..

Comments: I wrote a PBN computer game several years ago, and find myself solving these puzzles a lot, so I took this one on and solved it.  Using pencil and paper is quite a step back after using the mouse all this time.  :-)

I feared that it was going to be harder than it was and would rely much more on the fact that each of the "blobs" would have five squares that were separated from each other.  I've seen a couple of PBN "Plus" puzzles in Games World of Puzzles over the years, and they were all killers.  I'd be interested to know if other contestants stayed away from this or got stuck, because there were only six people who entered solutions during the contest.