a1,6895.854,449.517
a2,6186.659,423.715
a3,5031.439,598.862
a4,5101.541,1050.105
*********************
1,6127.3494,630.8833
2,5988.0827,795.6415
3,5492.7946,802.3349
4,5398.2769,712.1753
**********
a2,a1,1
1,a2,2
2,1,3
3,2,4
4,3,a3
a3,4,a4
***********
a2,1
1,2
2,3
3,4
4,a3