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

Difficulty: Hard (0)

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

Difficulty: Very easy (0)

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

Difficulty: Very easy (0)

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

Difficulty: Easy (0)