Chanting at the Asylum

A man is walking down the road one day, when he passes by an insane asylum. As he strolls by the asylum, he hears the people inide the walls of the compound chanting thirteen! Another, and another chanted "thirteen, thirteen". As his curiosity kicked in, he decided to see why they were chanting thirteen. He quickly finds a hole in the wall, and peeks through...

POKE!!! Right in his eye! "Fourteen, fourteen, fourteen!"