A young man was strolling down a street. As he passed a sanatorium with a fence around it, he heard a group of people chanting, "Thirteen, thirteen, thirteen..." over and over again.
Curious, he tried to see over the fence, but couldn't. Then he spotted a hole in the wood.
He put his eye to the hole. He just managed to spy some people sitting in rocking chairs chanting, before a finger came out of nowhere and poked him in the eye. As he staggered back, the people started chanting, "Fourteen, fourteen, fourteen..."