1				6								5
		14	6	4					13					12
	13									1
	7		12				11		3
				12				7		16		10		15
	11	16			2	15	5			14
	14			11	13	16							6
		2								12
					11								9
		4							6	11	9			2
					15			13	10	8			5	6
	12		14		3		9				1
						2		4				15		5
					12									7
	5					4					15	2	14
8								3				16

Difficulty: Easy (0)

9	4				3							12	7
			8					14							13
		11		14		10	4	2
								9			3
	2		3						6			16
		9		12								1		14
						8					11				9
		13	11	3	5			16			8		10
		8		1			3			6	15	4	16
5				2					4
	7		14								16		5
			1			4						3		9
				8			13
							10	7	16		14		6
8							16					9
		7	2							1				8	5

Difficulty: Very easy (0)

		3	6							9
				4											6
	13				11	6		3					14		12
				9			12	10						15
		13			16			9		2	4	12
14	12	16									5
		2					9	15					16		13
	7		15											1
	15											9		5
12		7					5	14					13
				8									7	14	4
			4	7	10		1			5			12
	9						15	4			11
7		14					2		1	3				16
5											6
					7							8	11

Difficulty: Hard (0)

	9					2		16
					16			10				5
16				4	3							11	6
13										7	6		1
				10					12		15
								13	1						15
9			14											1
6							4	3		5	7	10	11
		6	11	5	4		1	12							3
	5											8			4
4						12	11
				16		3					2
		9		15	11										16
		8	10							12	9				14
			16				13			3
							10		13					4

Difficulty: Easy (0)