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

Difficulty: Medium (0)

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

Difficulty: Very hard (0)

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

Difficulty: Very easy (0)

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

Difficulty: Super easy (0)