The cafeteria is dark except for one light in the kitchen. The cafeteria manager is in there, counting lunch money. She says that there were some strangers in the school today and they ate lunch in the cafeteria. "They paid cash and ate their lunches. They didn't even put their lunch trays up and wipe off the table. We even found their receipts on the floor!" You pick up the receipts, thinking they might be a clue. Look them over carefully. Check over the numbers and letters in every direction. Hackers love letters and numbers because they are a part of writing code!
When you figure out the clue, go back to the home page and enter it into the hackers' database.