(define cchar-clist (string-split "ZYXWVUTSRQPONMLKJIHGFEDCBA" ""))

(set-cdr! (last-pair cchar-clist) cchar-clist)

(define (char-shift c x)
  (car (drop (member c cchar-clist) x))
  )

(define (decode str)
  (define (dec-iter i sl r)
    (if (null? sl) (string-join (reverse r) "")
	(dec-iter
	 (+ i 1)
	 (cdr sl)
	 (cons (char-shift (car sl) i) r)))
    )
   (dec-iter 1 (string-split str "") ())
  )

(define (main _)
  (display (decode (read-line)))
  (newline)
  0)