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

Difficulty: Easy (0)

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

Difficulty: Very easy (0)

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

Difficulty: Medium (0)

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

Difficulty: Very easy (0)