>>writegraph3d planar <<
1 0 0 0 2 3 4
2 0 0 0 1 4 7 5
3 0 0 0 1 5 6
4 0 0 0 1 6 7 2
5 0 0 0 2 7 3
6 0 0 0 3 7 4
7 0 0 0 4 6 5 2
0
