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

Difficulty: Easy (0)

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

Difficulty: Super easy (0)

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

Difficulty: Easy (0)

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

Difficulty: Super easy (0)