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

Difficulty: Very easy (0)

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

Difficulty: Very easy (0)

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

Difficulty: Super easy (0)

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

Difficulty: Easy (0)