4		1		9
						2
	1						7
				9
								7
					8			5
				7
		5	8					2

Difficulty: Very easy (0)

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

Difficulty: Super easy (0)

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

Difficulty: Very easy (0)

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

Difficulty: Very hard (0)