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

import static java.lang.Math.*;

public class Main {
    FastScanner in;
    PrintWriter out;

    static final String FILE = "";

    void solve() {
        int n = in.nextInt();
        String s = in.next();
        List<Integer> list = new ArrayList<>();
        for (Character c : s.toCharArray()) {
            int v = c - '0';
            if (v == 2) {
                list.add(2);
            } else if (v == 3) {
                list.add(3);
            } else if (v == 4) {
                list.add(2);
                list.add(2);
                list.add(3);
            } else if (v == 5) {
                list.add(5);
            } else if (v == 6) {
                list.add(5);
                list.add(3);
            } else if (v == 7) {
                list.add(7);
            } else if (v == 8) {
                list.add(7);
                list.add(2);
                list.add(2);
                list.add(2);
            } else if (v == 9) {
                list.add(7);
                list.add(3);
                list.add(3);
                list.add(2);
            }
        }
        Collections.sort(list, Collections.reverseOrder());
        for (Integer it : list)
            out.print(it);
    }

    public void run() {
        if (FILE.equals("")) {
            in = new FastScanner(System.in);
            out = new PrintWriter(System.out);
        } else {
            try {
                in = new FastScanner(new FileInputStream(FILE +
                        ".in"));
                out = new PrintWriter(new FileOutputStream(FILE +
                        ".out"));
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            }
        }
        solve();
        out.close();
    }

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

    class FastScanner {
        BufferedReader br;
        StringTokenizer st;

        public FastScanner(InputStream is) {
            br = new BufferedReader(new InputStreamReader(is));
        }

        public String next() {
            while (st == null || !st.hasMoreTokens()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

        public String nextLine() {
            st = null;
            try {
                return br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
                return null;
            }
        }

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

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

        public double nextDouble() {
            return Double.parseDouble(next());
        }

        public float nextFloat() {
            return Float.parseFloat(next());
        }
    }

}