#				-
0	1	2-5	6-13	14-20
1	1	2-4	5-9	10-17	18-20
2	1	2-4	5-7	8-16	17-18	19-20
3	1	2-3	4-6	7-15	16-17	18-19	20
4	1	2-3	4-5	6-14	15-17	18-19	20
5	1	2	3-4	5-13	14-16	17-19	20
6	1	2	3-4	5-11	12-15	16-19	20
7		1	2-3	4-10	11-14	15-18	19-20
8		1	2	3-8	9-12	13-18	19-20
9			1	2-7	8-10	11-17	18-20
10			1	2-5	6-8	9-17	18-20
11			1	2-4	5-8	9-16	17-20
12				1-2	3-6	7-15	16-20