static double computeArea(Circle cs[]){
        double ans = 0.0;
        for (int i = 0; i < cs.length; ++i){
            boolean flag = false;
            for (int j = i+1; j < cs.length; ++j){
                if (cs[i].isIntersected(cs[j]) || cs[i].contains(cs[j])){
                    flag = true;
                    break;
                }
            }
            if (!flag){
                ans += cs[i].getArea();
            }
        }
        return ans;
    }