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