static String aDecentNumber(int n) {
        int temp = n;
        while (temp >= 3) {
            if (temp % 3 == 0) {
                return fillNo(5, temp) + fillNo(3, n - temp);
            }
            temp -= 5;
            if (temp == 0) {
                return fillNo(3, n);
            }
        }
        return "-1";
    }

    static String fillNo(int no, int times) {
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < times; i++) {
            sb.append(no);
        }
        return sb.toString();
    }