function calcDepth(orders) {
    var base = parseInt(orders[0].Price);
    var allAmount = 0;
    var n = 0;
    for (var i = 0; i < orders.length && n < DepthLevel; i++) {
        var p = parseInt(orders[i].Price);
        if (p != base) {
            n++;
            base = p;
        }
        allAmount += orders[i].Amount;
    }