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

Difficulty: Very easy (0)

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

Difficulty: Easy (0)

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

Difficulty: Very easy (0)

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

Difficulty: Easy (0)