Griddler, also known as Paint by Numbers or Nonograms are picture logic puzzles in which cells in a grid have to be colored or left blank according to numbers given at the side of the grid to reveal a hidden picture. In this puzzle type, the numbers measure how many unbroken lines of filled-in squares there are in any given row or column. For example, a clue of “4 8 3″ would mean there are sets of four, eight, and three filled squares, in that order, with at least one blank square between successive groups.