alp="ABCDEFGHIJKLMNOPQRSTUVWXYZ"

s=input()
n=len(s)
ans=""
for i in range(n):
    ind=alp.index(s[i])-i-1
    if ind<0:
        ind+=len(alp)
        ind%=len(alp)
    ans+=alp[ind]
print(ans)