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

Difficulty: Super easy (0)

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

Difficulty: Very easy (0)

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

Difficulty: Easy (0)

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

Difficulty: Very easy (0)