4
9		7	5	4				8
								4
						2
	7	5	8		2	6	3
		9
7
5				9	3	1		6
						5

Difficulty: Medium (0)

	5				4		3
6			7	3				9
9							1
			2	6
		6				4
				4	5
	3							1
7				5	2			3
	6		8				5

Difficulty: Hard (0)

9			5			1		3
								2
					8
						4
4	2	1				5	9	8
		7
			9
2
8		5			7			4

Difficulty: Hard (0)

2		8			7		3
			5				9
		4			1			7
						5		2
				5
5		9
7			4			9
	3				9
	9		3			4		1

Difficulty: Easy (0)