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

Difficulty: Easy (0)

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

Difficulty: Very easy (0)

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

Difficulty: Easy (0)

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

Difficulty: Super easy (0)