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

Difficulty: Super easy (0)

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

Difficulty: Very hard (0)

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

Difficulty: Hard (0)

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

Difficulty: Easy (0)