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

Difficulty: Very easy (0)

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

Difficulty: Very easy (0)

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

Difficulty: Very easy (0)

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

Difficulty: Very hard (0)