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

Difficulty: Medium

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

Difficulty: Medium

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

Difficulty: Medium

9			8					6
8	10				7	11
		9
						11
	10		3				5
3				1
4		4			2
1				2		5	7	6

Difficulty: Super easy