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

Difficulty: Very easy (0)

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

Difficulty: Easy (0)

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

Difficulty: Very easy (0)

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

Difficulty: Easy (0)