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

Difficulty: Medium

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

Difficulty: Easy

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

Difficulty: Medium

				4	3		1	6
3	7	5					6
5
						2
						1
	7			4			2

Difficulty: Super easy