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

Difficulty: Very easy (0)

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

Difficulty: Very hard (0)

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

Difficulty: Easy (0)

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

Difficulty: Very easy (0)