S = input()

alphabet = [
    "A","B","C","D","E","F","G","H","I","J","K","L","M",
    "N","O","P","Q","R","S","T","U","V","W","X","Y","Z"
]

ans = ""

for i in range(len(S)):
    index = alphabet.index(S[i]) - i - 1
    index %= 26
    ans += alphabet[index]

print(ans)