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

Difficulty: Super easy (0)

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

Difficulty: Easy (0)

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

Difficulty: Medium (0)

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

Difficulty: Super easy (0)