While wandering aimlessly through the lost desert, a mysterious Yurble approaches you.
"Psst... wanna buy some Useless Crystals? Only 200 Neopoints for four. If you can solve their riddle, you might be able to obtain a treasure...."
You hand over your money and he scurries off. Then you examine your "crystals" and see they're not crystals at all, just ordinary, even-more-useless glass. They're not even high-quality glass; they have these odd markings all over them:
What is the answer to this puzzle?