origin	destination	travel time
0	1	2.0
0	2	4.0
1	0	2.0
1	2	4.0
2	0	4.0
2	1	4.0
0	1	0.0
0	2	0.0
1	0	0.0
1	2	0.0
2	0	0.0
2	1	0.0