Nonogram

Nonograms, also called Paint by Numbers, Picross, or Griddler, are a popular type of puzzle where you paint a picture by following the rules of the puzzle. Numbers are placed on the top and left edges of the grid and indicate how many contiguous colored squares appear in that row or column. For example, a clue of "2 4" on a row would mean that you would expect to see a block of two colored cells, followed by a space of some length followed by a block of four colored cells. These types of puzzles can produce a black and white picture or colored picture. In the case of a colored image, the number clues would be colored to indicate how to fill in the grid.