main::IO()
main = do
  xs <-getLine
  let kaijou 0 = 1
      kaijou n = n * kaijou (n-1)
      nC2 n 
        |n<2    = 0
        |otherwise = n * (n-1) `div` 2
      exe _ [] =[]
      exe n (x:xs)
        |x=='c'    = (nC2 n):exe n xs
        |x=='w'    = exe (n+1) xs
        |otherwise = exe n xs

  print . sum . exe 0 $reverse xs