import qualified Data.ByteString.Lazy.Char8 as C

combi :: Integral a => a -> a
combi n = n * (n - 1) `div` 2

solve :: Integral a => C.ByteString -> a
solve = snd . C.foldr sol (0, 0)
    where
        sol c (w, x)
            | c == 'w' = (w + 1, x)
            | c == 'c' && w > 0 = (w, x + combi w)
            | otherwise = (w, x)

main :: IO ()
main = print . solve =<< C.getContents