#coding: utf-8
##yuki_18

s=raw_input()
l=list(s)

for i in xrange(len(l)):
 od=ord(l[i])
 od_t=od-i-1
 while od_t<65:
  od_t=od_t+26
 l[i]=chr(od_t)

s="".join(l)
print s