import sys
import os
from Crypto.Cipher import AES

MESSAGE = b"GET FILE: flag.txt"
QUERIES = []
BLOCK_SIZE = 16
KEY = os.urandom(BLOCK_SIZE)


def oracle(message: bytes) -> bytes:
    aes_ecb = AES.new(KEY, AES.MODE_ECB)
    return aes_ecb.encrypt(message)[-BLOCK_SIZE:]


def main():
    for _ in range(3):
        command = sys.stdin.buffer.readline().strip()
        tag = sys.stdin.buffer.readline().strip()
        if command in QUERIES:
            print(b"Already queried")
            continue

        if len(command) % BLOCK_SIZE != 0:
            print(b"Invalid length")
            continue

        result = oracle(command)
        if command.startswith(MESSAGE) and result == tag and command not in QUERIES:
            with open("flag.txt", "rb") as f:
                sys.stdout.buffer.write(f.read())
                sys.stdout.flush()
        else:
            QUERIES.append(command)
            assert len(result) == BLOCK_SIZE
            sys.stdout.buffer.write(result + b"\n")
            sys.stdout.flush()


if __name__ == "__main__":
    main()