reduce {
  %s = $1
  tokenize 2 abcdefghijklmnopqrstuvwxyzzyxwvutsrqponmlkjihgfedcba
  a $*
  return %s
}
a {
  %l = 26
  while %l > 2 {
    %p = 1
    while %p < $calc(28-%l) {
      %s = $replace(%s,$mid($1,%p,%l),$+($mid($1,%p,1),-,$mid($1,$calc(%p -1+%l),1)))
      inc %p
    }
    dec %l
  }
}