function main() {
    var ag_iter = AdsApp.adGroups()
        .withCondition("Status = ENABLED")
        .withCondition("CampaignName CONTAINS_IGNORE_CASE 'MyCampaignName'")
        .withCondition("Impressions > 1000")
        .forDateRange("LAST_30_DAYS")
        .get();

    while (ag_iter.hasNext()) {
        var ag = ag_iter.next();
        Logger.log(ag.getName())

        var ad_iter = ag.ads()
            .withCondition("Status = ENABLED")
            .forDateRange("LAST_30_DAYS")
            .orderBy("Ctr ASC")
            .get();


        var ad_array = new Array();
        while (ad_iter.hasNext()) {
            ad_array.push(ad_iter.next());

        }

        var ads_to_leave = 1;

        if (ad_array.length > ads_to_leave ) {
            for (var i = 0; i < ad_array.length - (ads_to_leave + 1); i++) {
                ad_array[i].pause();
            }
        }
    }
}