def to_ord(s: str):
    return ord(s) - 65


def to_chr(c):
    return chr(c+65)


S = input()
len_S = len(S)

code = list(map(to_ord, S))
shift = list(range(1, len(S) + 1))
ans_code = [(i - j) % 26 for i, j in zip(code, shift)]

ans = ''.join(map(to_chr, ans_code))
print(ans)