def decrypt_u_sa_code(S):
    decrypted = []
    for i, c in enumerate(S):
        shift = (ord(c) - ord('A') - (i + 1)) % 26
        decrypted.append(chr(ord('A') + shift))
    return ''.join(decrypted)

# 入力の取得
S = input()

# 復号した文字列の出力
print(decrypt_u_sa_code(S))