alpha = [chr(ord("A") + i) for i in range(26)]
def get_alphabet_after_n(current = "A",next = 1):
    current = ord(current) - 65
    next=current-next
    next%=26
    if next < 0:
        next+=26
    return alpha[next]

S = input()
usa = ""
for i,s in enumerate(S):
    usa+=get_alphabet_after_n(s,i + 1)
print(usa)