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

Difficulty: Super easy (0)

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

Difficulty: Hard (0)

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

Difficulty: Hard (0)

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

Difficulty: Very easy (0)