def decrypt(flag_enc: str) -> str:
    offset = 13
    flag = ""
    for letter in flag_enc:
        if letter.isalpha():
            if letter.isupper():
                flag += chr((ord(letter) - ord('A') - offset) % 26 + ord('A'))
            else:
                flag += chr((ord(letter) - ord('a') - offset) % 26 + ord('a'))
        else:
            flag += letter
    return flag

flag_enc = open("flag.enc").read()
print(decrypt(flag_enc))