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

Difficulty: Easy (0)

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

Difficulty: Very easy (0)

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

Difficulty: Easy (0)

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

Difficulty: Easy (0)