blzh hid his message in a QR code.
To ensure safety, he ripped it in 4 pieces and told blzhquest organizers to keep it safely. Orgas took responsibility and keep the flag parts near their PHDays badges. But it turns out, blzh overshoot and gave the pieces to 10 orgas!
Spot any 4 blzhquest orgas on the convention, get the QR together, and figure out blzh's message!