Keep at 666 XUts3HZ

var f = function() {
    var keepAt = 666;
    var score = parseInt($('.points-XUts3HZ').text());
    var isUpPushed = $('#mainUpArrow').hasClass('pushed');
    var isDownPushed = $('#mainDownArrow').hasClass('pushed');

    if(score > keepAt && !isDownPushed) {
        if(score == keepAt + 1 && isUpPushed) {
            $('#mainUpArrow').click();
        } else {
            $('#mainDownArrow').click();
        }
    }

    if(score < keepAt && !isUpPushed) {
        if(score == keepAt - 1 && isDownPushed) {
            $('#mainDownArrow').click();
        } else {
            $('#mainUpArrow').click();
        }
    }
};

setInterval(f, 1000);