S = input()
ordA = ord('A')
ordZ = ord('Z')
mod = ordZ - ordA + 1
deciphered = []
for i, c in enumerate(S, 1):
    ordC = ord(c)
    ordD = ordA + ((ordC - ordA - i) % mod)
    deciphered.append(chr(ordD))
print(''.join(deciphered))