Obama family tree

I figured that, as a good American, I ought to familiarize myself with our soon-to-be First Family: the Obamas.

"Aunt Zeituni and Uncle Omar are the children of Mr Obama’s grandfather Hussein Onyango Obama, by his third wife – the woman Mr Obama calls “Granny” because she raised his father. Mr Obama’s father, Barack Sr, was Onyango Obama’s son by his second wife, Akumu. That makes Zeituni and Omar a half-sister and half-brother of Mr Obama’s father, or Mr Obama’s half-aunt and half-uncle."

Come again?