st = list(raw_input())
al = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
enc = dict(zip(al, range(26)))
dec = dict(zip(range(26), al))
ans = []
for i in range(len(st)):
    digit = enc[st[i]] - ((i + 1) % 26)
    if digit < 0:
        ans.append(dec[digit + 26])
    else:
        ans.append(dec[digit])

print ''.join(ans)