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