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

Difficulty: Very easy (0)

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

Difficulty: Very hard (0)

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

Difficulty: Harder (0)

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

Difficulty: Medium (0)