7
0	2	1 1.0	3 1.0
1	2	0 1.0	2 1.0
2	3	1 1.0	3 1.0	6 1.0
3	4	0 1.0	2 1.0	4 1.0	5 1.0
4 	2	3 1.0	5 1.0
5	2	3 1.0	4 1.0
6	1	2 1.0