def METHOD_NAME(s: BytesIO) -> int:
    # 2.2.2.2.1.2.1.3
    msb = Uint8.unpack(s)
    val = msb & 0x3F
    if msb & 0x80:
        lsb = Uint8.unpack(s)
        val = (val << 8) | lsb
    return -val if msb & 0x40 else val