Technically, requires 2D logic, but is a VERY good one for first time, as Teesea points out.
Use temps, "assume" the 9 starts in the top right-most pixel, and go until you get a contradiction, you'll know the square you started from CAN'T be filled in, keep going like that until you can prove something else 8D
A wonderful puzzle, and a very clever little image 8D.
Use temps, "assume" the 9 starts in the top right-most pixel, and go until you get a contradiction, you'll know the square you started from CAN'T be filled in, keep going like that until you can prove something else 8D
A wonderful puzzle, and a very clever little image 8D.