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

Difficulty: Very easy (0)

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

Difficulty: Medium (0)

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

Difficulty: Very easy (0)

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

Difficulty: Very easy (0)