I guess I could only say that we started off looking at forest residues. The history of the country was first forest residues and then agricultural residues, but it was much easier to collect agricultural residues. The baling equipment and everything is all there, available. Gathering forest residues is a bit of a challenge, but eventually we would expect to be able to not just use agricultural residues but also eventually forest residues.
As to the question of whether or not you can have a grain ethanol plant and then switch it to a cellulose ethanol plant, some of the parts would be complementary. There are tanks and distillation columns that you could use. Obviously we use different yeasts and different enzymes, and there's pre-treatment that is different. You couldn't switch back and forth between starch and cellulose, but you could perhaps convert a plant at some point if it seemed like a sensible business decision.