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

Difficulty: Super easy (0)

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

Difficulty: Easy (0)

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

Difficulty: Medium (0)

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

Difficulty: Very easy (0)