Unrecognized flag "--" - ignored
ill-formed integer "elp" in flag -h
Usage: /usr/bin/gvgen [-dv?] [options]
 -c<n>         : cycle
 -C<x,y>       : cylinder
 -g[f]<h,w>    : grid (folded if f is used)
 -G[f]<h,w>    : partial grid (folded if f is used)
 -h<x>         : hypercube
 -k<x>         : complete
 -b<x,y>       : complete bipartite
 -B<x,y>       : ball
 -i<n>         : generate <n> random
 -m<x>         : triangular mesh
 -M<x,y>       : x by y Moebius strip
 -n<prefix>    : use <prefix> in node names ("")
 -N<name>      : use <name> for the graph ("")
 -o<outfile>   : put output in <outfile> (stdout)
 -p<x>         : path
 -r<x>,<n>     : random graph
 -R<n>         : random rooted tree on <n> vertices
 -s<x>         : star
 -S<x>         : 2D sierpinski
 -S<x>,<d>     : <d>D sierpinski (<d> = 2,3)
 -t<x>         : binary tree
 -t<x>,<n>     : n-ary tree
 -T<x,y>       : torus
 -T<x,y,t1,t2> : twisted torus
 -u<seed>      : state for random number generation
 -w<x>         : wheel
 -d            : directed graph
 -v            : verbose mode
 -?            : print usage