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

Difficulty: Medium

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

Difficulty: Medium

	1							2
	8		3			5
		4			10
					4
			6				10
		3
							7	9
	6	8				7	9
1				5				2

Difficulty: Medium

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

Difficulty: Medium