As Agnes turned round again she saw the three magpies. They were perched on a branch over the road.

“‘Three for a funeral-‘” she began.

A stone whirred up. There was an indignant squawk and a shower of feathers.

“Two for mirth,” said Nanny, in a self-satisfied voice.

“Nanny, that was cheating.”

“Witches always cheat,” said Nanny Ogg. She glanced back at the sleeping figure behind them. “Everyone knows that - who knows anything about witches."
--- Terry Pratchett, "Carpe Jugulum"