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

Difficulty: Easy (0)

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

Difficulty: Very easy (0)

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

Difficulty: Easy (0)

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

Difficulty: Very hard (0)