One for Sorrow is a traditional children's nursery rhyme about magpies. According to an old superstition, the number of magpies one sees determines if one will have bad luck or not.
One for sorrow, Two for joy, Three for a girl, Four for a boy, Five for silver, Six for gold, Seven for a secret, Never to be told. Eight for a kiss, Nine for a wish, Ten for a bird You must not miss." Counting Crows