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

Difficulty: Super easy (0)

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

Difficulty: Very easy (0)

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

Difficulty: Very easy (0)

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

Difficulty: Medium (0)