Drazil is playing a math game with Varda.

Let's define <image> for positive integer x as a product of factorials of its digits. For example, <image>.

First, they choose a decimal number a consisting of n digits that contains at least one digit larger than 1. This number may possibly start with leading zeroes. Then they should find maximum positive number x satisfying following two conditions:

1. x doesn't contain neither digit 0 nor digit 1.

2. <image> = <image>.

Help friends find such number.

Input

The first line contains an integer n (1 ≤ n ≤ 15) — the number of digits in a.

The second line contains n digits of a. There is at least one digit in a that is larger than 1. Number a may possibly contain leading zeroes.

Output

Output a maximum possible integer satisfying the conditions above. There should be no zeroes and ones in this number decimal representation.

Examples

Input

4
1234


Output

33222


Input

3
555


Output

555

Note

In the first case, <image>
//package codeforces150217;

/**
 *
 * @author Nur Endah
 */
import java.util.ArrayList;
import java.util.Scanner;

public class c1 {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = Integer.parseInt(in.nextLine());
        String a = in.nextLine();
        ArrayList<Integer> ar = new ArrayList<Integer>();
        for (int i = 0; i < a.length(); i++) {
            int now = Integer.parseInt(a.substring(i, i + 1));
            if (now == 2) {
                ar.add(2);
            }
            if (now == 3) {
                ar.add(3);
            }
            if (now == 4) {
                ar.add(3);
                ar.add(2);
                ar.add(2);
            }
            if (now == 5) {
                ar.add(5);
            }
            if (now == 6) {
                ar.add(5);
                ar.add(3);
            }
            if (now == 7) {
                ar.add(7);
            }
            if (now == 8) {
                ar.add(7);
                ar.add(2);
                ar.add(2);
                ar.add(2);
            }
            if (now == 9) {
                ar.add(7);
                ar.add(3);
                ar.add(3);
                ar.add(2);
            }
        }
        ar.sort(null);
        String out = "";
        for (int i = ar.size(); i > 0; i--) {
            out = out + "" + ar.get(i - 1);
        }
        System.out.println(out);
    }
}
