main :: IO ()
main = do s_ <- getLine
          let s = filter (\x -> x == 'c' || x== 'w') s_
          putStrLn . show $ f s

f :: String -> Int
f ('c':xs) | length s < 2 = 0
           | otherwise = bc (length s) 2 + f xs
    where s = filter ((==) 'w') xs
f (_:xs) = f xs
f _ = 0

bc :: Int -> Int -> Int
bc _ 0 = 1
bc n k | n < 0 = 0
       | n == k = 1
       | otherwise = bc (n - 1) (k - 1) + bc (n - 1) k