# -*- coding: utf-8 -*-

txt = map(str, raw_input())

for i in range(len(txt)):
    N = (i + 1) % 26
    if ord(txt[i]) - N >= 65:
        txt[i] = chr(ord(txt[i]) - N)
    else:
        txt[i] = chr(ord(txt[i]) - N + 26)
print "".join(txt)