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

Difficulty: Easy

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

Difficulty: Medium

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

Difficulty: Medium

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

Difficulty: Medium