Nonogram
Nonogram A Nonogram – is a puzzle, which has a picture encoded in numbers. The aim of the puzzle is to restore this picture in full.
Nonograms are also known by many other names, including Paint by Numbers, Griddlers, Pic-a-Pix, Picross, PrismaPixels, Pixel Puzzles, Crucipixel, Edel, FigurePic, Hanjie, HeroGlyphix, Illust-Logic, Japanese Crosswords, Japanese Puzzles.
The rules are simple. You have a grid of squares, which must be either filled in black or marked with X.