It is carpet, per section 2.2.1 of part 2 of the
Game Manual. I do not mean this to lack any charity and would ask that you DO ask questions here and participate in this wonderful community. That said, I would ask that you download at least the entire game manual (the administrative side is probably less relevant) and read it cover to cover.
Not only will it illustrate in no uncertain terms what you can and cannot do in the season, but it will also really help you brainstorm and get you thinking about ways to win that might be less mainstream. That's a big deal, really!
Again, if there are ways for us to help, let us know, but let your first resource be the manual. Print a copy and keep it by your bed for the next couple months. Nothing sucks worse than being at fault for a penalty you didn't know existed, or straight-up not passing inspection because you missed something.
Now go get engineering!