def ISO_6391_to_6392(code: str) -> str:
    """
    Converts ISO 639-1 (2 letters) language codes to ISO 639-2 (3 letters)
    """
    if code == "ca":
        return "cat"
    if code == "da":
        return "dan"
    elif code == "en":
        return "eng"
    elif code == "es":
        return "spa"
    elif code == "it":
        return "ita"
    elif code == "mn":
        return "mon"
    elif code == "zh":
        return "cmn"
    else:
        raise ValueError("ISO 639-1 code not known: "+str(code))