def make_alphabet():
    chars = [chr(i) for i in range(ord('ก'), ord('ก') + 47)]   # ก... (47 ตัว)
    chars += [chr(i) for i in range(ord('๐'), ord('๐') + 10)]  # ๐-๙ (10 ตัว)
    chars += [chr(i) for i in range(ord('0'), ord('0') + 10)]  # 0-9 (10 ตัว)
    return chars[:64]

ALPHABET = make_alphabet()
ALPH2VAL = {c: i for i, c in enumerate(ALPHABET)}

def custom64_to_int(s):
    value = 0
    for ch in s:
        if ch not in ALPH2VAL:
            raise ValueError(f"Alphabet NOT FOUND IN: {ch!r}")
        value = value * 64 + ALPH2VAL[ch]
    return value

def decode_custom_base64(enc_text):
    if enc_text.endswith("=="):
        enc_text = enc_text[:-2]
    n = custom64_to_int(enc_text)
    hex_str = format(n, "x")
    if len(hex_str) % 2 == 1:
        hex_str = "0" + hex_str
    data = bytes.fromhex(hex_str)
    return data.decode("utf-8", errors="replace")

if __name__ == "__main__":
    import pathlib

    enc_path = pathlib.Path("enc.txt")
    enc_text = enc_path.read_text(encoding="utf-16").strip()
    result = decode_custom_base64(enc_text)
    print(result)