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

Difficulty: Very easy (0)

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

Difficulty: Medium (0)

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

Difficulty: Very easy (0)

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

Difficulty: Very easy (0)