def main():
    S = input()

    ans = ''
    l = len(S)
    for i in range(l):
        befor = ord(S[i])
        after = befor - (i + 1) % 26
        if after < 65:
            after = 90 - (64 - after)
        ans = ans + chr(after)

    print(ans)

main()