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An interesting variant of the normal minesweeper is so-called "knights" minesweeper. In this version of the game, instead of the number telling you how many mines are toughing each square, it tells you have many mines are a chess knight move away. In other words, it tells how many mines are in any one of the following locations:

up two, left one
up two, right one
down two, left one
down two, right one
up one, left two
up one, right two
down one, left two
down one, right two