LoadPackage("orb");
LoadPackage("genss");
ComputeStabiliserMC := function(g,x,op,N)
  local h,i,l,o,p,pr,w,y;
  Print("Enumerating orbit...\n");
  o := Orb(g,x,op,rec( treehashsize := 100000, report := 100000,
                       schreier := true ));
  Enumerate(o);
  Print("done, computing generators for stabiliser...\n");
  pr := ProductReplacer(g);
  l := [];
  for i in [1..N] do
    h := Next(pr);
    y := op(x,h);
    p := Position(o,y);
    if p <> 1 then
      w := TraceSchreierTreeForward(o,p);
      Add(l,h / Product(GeneratorsOfGroup(g){w}));
    else
      Add(l,h);
    fi;
  od;
  Print("done.\n");
  return l;
end;