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

Difficulty: Medium

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

Difficulty: Medium

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

Difficulty: Medium

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

Difficulty: Medium