import java.util.*;

public class Run {
    public static void main (String arg[]) {
        Scanner scan = new Scanner(System.in);
        String ans = "";
        String N = scan.next();
        String tmp = "", one = "", two = "", three = "", four = "", five = "", six = "", seven = "", eight = "", nine = "", zero = "";
        for (int i = 0; i < N.length(); i++) {
            tmp = N.substring(i, i+1);
            if (tmp.equals("1")) one += tmp;
            else if (tmp.equals("2")) two += tmp;
            else if (tmp.equals("3")) three += tmp;
            else if (tmp.equals("4")) four += tmp;
            else if (tmp.equals("5")) five += tmp;
            else if (tmp.equals("6")) six += tmp;
            else if (tmp.equals("7")) seven += tmp;
            else if (tmp.equals("8")) eight += tmp;
            else if (tmp.equals("9")) nine += tmp;
            else zero += tmp;
        }
        ans = nine + eight + seven + six + five + four + three + two + one + zero;
       System.out.println(ans);
    }
}