def get_all_not_used_templates(used_templates, all_templates):
    """
    Chooce not used template among all templates

    Args:
        used_templates: list of templates already used in the dialog
        all_templates: list of all available templates

    Returns:
        string template
    """
    available = list(set(all_templates).difference(set(used_templates)))
    if len(available) > 0:
        return available
    else:
        return all_templates