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

Difficulty: Hard (0)

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

Difficulty: Very easy (0)

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

Difficulty: Very easy (0)

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

Difficulty: Easy (0)