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

Difficulty: Very hard (0)

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

Difficulty: Very hard (0)

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

Difficulty: Very easy (0)

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

Difficulty: Very easy (0)