There were only four witches in all the Land of Oz, and two of them, those who live in the North and the South, are good witches. I know this is true, for I am one of them myself, and cannot be mistaken. Those who dwelt in the East and the West were, indeed, wicked witches; but now that you have killed one of them, there is but one Wicked Witch in all the Land of Oz — the one who lives in the West.
The Wonderful Wizard of Oz (1900)