Nonograms are picture logic puzzles with cells in a grid that are colored or left blank to reveal a hidden picture. The choice of which cells to color or leave blank is determined by the numbers that are placed on the top and the side of the grid. This brings about the concept of picture crosswords, and therefore, the name Picross. Nonograms originated from Japan when Non Ishida won a design competition by using skyscrapers lights to imitate the grid pictures that are characteristic of the game. In the subsequent years, the game made great strides by making it to popular magazines in Japan and finally traversing to other parts of the world.