S = list(input())
box=[]
for i in range(len(S)):
    if 65<=ord(S[i])-(i+1)<=90:
        box.append(ord(S[i])-(i+1))
    else:
        box.append(((ord(S[i])-65-(i+1))%26)+65)

ans=[]
for n in box:
    ans.append(chr(n))

print("".join(ans))