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

Difficulty: Very easy (0)

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

Difficulty: Very easy (0)

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

Difficulty: Easy (0)

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

Difficulty: Super easy (0)