program main
  implicit none
  character*100000::S
  integer::len,wpos,cnum,wnum
  read *,S
  len = LEN_TRIM(S)
  wpos = SCAN(TRIM(S), 'w')
  cnum = wpos-1
  wnum = len-cnum
  print '(i0)',MIN(cnum-1,wnum)
end program main