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

Difficulty: Very easy (0)

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

Difficulty: Easy (0)

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

Difficulty: Very easy (0)

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

Difficulty: Very easy (0)