Hamusando ("Ham Sandwich") is a logic puzzle invented by Naoki Inaba (Japan). The goal is to fill a square grid with squares ("toasts") and circles ("pieces of ham"). Every row and every column contains two squares and N circles (N is given for each puzzle). A number at the edge of the grid indicates how many circles must be placed between the two squares in the corresponding row or column.
Cross+A can solve puzzles from