public static void main(String[] args) {
    // TODO Auto-generated method stub
    Scanner in = new Scanner(System.in);
    int tc = in.nextInt();
    while (tc-- > 0) {
        getNumbr(in.nextInt());
    }
    in.close();
}

private static void getNumbr(int n) {
    // TODO Auto-generated method stub
    int n5 = 0, n3 = 0;

    int nt = n;
    while (nt % 3 != 0) {
        nt -= 5;
        n3 += 1;
        if (nt < 3 && nt != 0) {
            System.out.println("-1");
            return;
        }
    }

    n5 = nt / 3;
    String s = "";

    for (int i = 0; i < n5; ++i) 
        s += "555"; 
    for (int i = 0; i < n3; ++i)
        s += "33333";

    for (int i = 0; i < s.length(); ++i)
        System.out.print(s.charAt(i));
    System.out.println();
}

could you please point out the inefficiency in printing in my case, as i am also getting timeout for 5-13.