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

Difficulty: Easy (0)

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

Difficulty: Very easy (0)

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

Difficulty: Very easy (0)

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

Difficulty: Very easy (0)