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

Difficulty: Very hard (0)

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

Difficulty: Super easy (0)

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

Difficulty: Super easy (0)

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

Difficulty: Very hard (0)