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>
/*
 * If you put a million monkeys at a million keyboards, one of them will eventually write a Java program.
 * The rest of them will write Perl programs.
 */

import java.util.*;
import java.io.*;

public class Dreamoon {

    private static void solve() {
        int n = nextInt();
        String s = next();
        ArrayList<Integer> ans = new ArrayList<>();
        for (char c : s.toCharArray()) {
            int val = c - '0';
            if (val == 0 || val == 1) {
                continue;
            }
            if (val == 2 || val == 3 || val == 5 || val == 7) {
                ans.add(val);
                continue;
            }
            if (val == 4) {
                ans.add(3);
                ans.add(2);
                ans.add(2);
                continue;
            }
            if (val == 6) {
                ans.add(5);
                ans.add(3);
                continue;
            }
            if (val == 8) {
                ans.add(7);
                ans.add(2);
                ans.add(2);
                ans.add(2);
                continue;
            }
            if (val == 9) {
                ans.add(7);
                ans.add(3);
                ans.add(3);
                ans.add(2);
                continue;
            }
        }
        Collections.sort(ans);
        Collections.reverse(ans);
        for (int x : ans) {
            out.print(x);
        }
        out.println();
    }

    private static void run() {
        br = new BufferedReader(new InputStreamReader(System.in));
        out = new PrintWriter(System.out);

        solve();

        out.close();
    }

    private static StringTokenizer st;
    private static BufferedReader br;
    private static PrintWriter out;

    private static String next() {
        while (st == null || !st.hasMoreElements()) {
            String s;
            try {
                s = br.readLine();
            } catch (IOException e) {
                return null;
            }
            st = new StringTokenizer(s);
        }
        return st.nextToken();
    }

    private static int nextInt() {
        return Integer.parseInt(next());
    }

    private static long nextLong() {
        return Long.parseLong(next());
    }

    public static void main(String[] args) {
        run();
    }
}
