Dear contest holder. I created something simple, like entries #38 & #47 where you can see the roof but letter "G" too, but in this case letter just "hidden", this roof just gives the hint. I put small rooftop on the bigger square so there hints for commercial roofing (big flat roof) and residential roofing (small rooftop). Let me know, what do you think. Thanks!
Rgds,
Denzu