def html_escape(input_string: str) -> str:
    """escape all the html content

    :param input_string: A string that may contain html tags
    :return: the string with all the html syntax escaped so that it will be
    safe to put the returned string to html
    """
    html_escape_table = {
        "&": "&amp;",
        '"': "&quot;",
        "'": "&apos;",
        ">": "&gt;",
        "<": "&lt;",
    }
    return "".join(html_escape_table.get(c, c) for c in input_string)