Some solutions for 4X4
..3..1..3..0....0..4..4..4....0..4..3..2....0..2..4..0....1..4..4..4
..3..0..0..1....1..0..0..1....3..0..0..4....2..0..0..1....1..0..0..1
..1..0..0..3....2..0..0..1....4..0..0..3....1..0..0..2....4..0..0..1
..3..3..1..0....1..2..4..0....2..3..4..2....2..4..2..0....4..1..4..3
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