HELP! My brain's dying. I need a good riddle or brain teaser or something.

Also, I just learnt recently that there is a tribe on an island somewhere that still lives as they always have, shoot arrows at any helicopters that pass over or try to land, and kill anybody unlucky enough to be washed up there. No-one, therefore, knows much about them or even how many there are. Bit unbelievable in this day and age, huh?

Sadly, I have nothing else tonight.