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

Difficulty: Medium

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

Difficulty: Easy

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

Difficulty: Medium

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

Difficulty: Medium