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

Difficulty: Medium (0)

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

Difficulty: Very easy (0)

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

Difficulty: Very easy (0)

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

Difficulty: Easy (0)