from collections import deque
S = list(input())
chr_list = [chr(i) for i in range(65,65+26)]

decord = []
for i, char in enumerate(S,1):
    r = deque(chr_list)
    idx = chr_list.index(char)
    r.rotate(i)
    deco_chr = r[idx]
    decord.append(deco_chr)

print(''.join(decord))