Locale.setDefault(Locale.US);
        ArrayList<Double> res = new ArrayList<Double>();
        while (hasNext()) {
            double a=nextDouble();
            res.add(Math.sqrt(a));
        }
        Collections.reverse(res);
        for (double a : res) {
            DecimalFormat df=new DecimalFormat("0.0000");
            System.out.println(df.format(a));
        }
                Judge status shows that this failed in test case 1.