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

Difficulty: Super easy (0)

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

Difficulty: Hard (0)

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

Difficulty: Easy (0)

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

Difficulty: Very easy (0)