Length(nt)	Charges
			
2		1
3		2
4		2
5		2
6		2
7		3
8		3
9		3	
10		3
11		3
12		4
13		4
14		4
15		4
16		4,5,6
17		4,5,6,7,8			
18		4,5,6,7,8
19		5,6,7,8,9
20		5,6,7,8,9