import math
import sys
def S(): return sys.stdin.readline().rstrip()
def I(): return int(sys.stdin.readline().rstrip())
def MI(): return map(int, sys.stdin.readline().rstrip().split())
def LI(): return list(map(int, sys.stdin.readline().rstrip().split()))
def LS(): return list(sys.stdin.readline().rstrip().split())

def derot_n(s, n):
    return chr(ord('Z') - (ord('Z')-ord(s)+n) % 26)

s = S()
ans = ""

for i in range(n:=len(s)):
    ans += derot_n(s[i], i+1)

print(ans)