5	4						1
	10					5
4		8			1	7		3
	9
8								4
	6								10
								2
	1		7	9			3		5
			4					6
	3						9	7

Difficulty: Very easy (0)

				1
4				7		1		2
	9								4
	1			3		5
10						4	5
		5	2						9
			7		1			9
8								3
	3		5		8				10
					4

Difficulty: Very easy (0)

	7	9		2					1
				10			2
	10	4		5				1	2
						10	7
2								8
	8								5
		10	5
8	9				5		6	4
		8			2
9					8		4	3

Difficulty: Very easy (0)

8	7								4
5					8
							8		2
9	4				10	6	1
		1	9				6
		8				2	4
		2	1	5				8	6
6		10
				1					3
3								1	10

Difficulty: Easy (0)