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

Difficulty: Easy (0)

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

Difficulty: Very easy (0)

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

Difficulty: Very easy (0)

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

Difficulty: Easy (0)