Logic Masters Deutschland e.V.

Place numbers into some cells in the grid such that all numbers form an orthogonally connected group, no 2x2 area is entirely numbered, and no stretch of four horizontally or vertically connected cells is all numbered or all empty.

Within a room, all numbers must be the same, and the number placed is equal to the count of numbers in that room. A clue in the top-left corner of a room, if given, indicates the amount of numbers in that room (or equivalently, the number to be placed in that room). Every room contains at least one number.

If two numbers in different rooms are adjacent, they must be different.

An 8x8 example is provided:

SudokuPad

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