solve :: String -> Integer -> Integer
solve [] _ = 0
solve ('c':xs) c = c * (c - 1) `div` 2 + solve xs c
solve ('w':xs) c = solve xs (c - 1)
solve (_:xs) c = solve xs c

main = do
	str <- getLine
	let count = fromIntegral $ length (filter (=='w') str)
	print $ solve str count