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.util.*;
import java.io.*;
import java.lang.*;
import java.math.*;

import static java.lang.Math.*;

public class Solution implements Runnable {
    
    void solve() throws Exception {
        int n = sc.nextInt();
        String s = sc.nextToken();
        ArrayList<Integer> a = new ArrayList<Integer>();
        for (int i = 0; i < n; i++) {
            int x = s.charAt(i) - '0';
            if (x == 0 || x == 1)
                continue;
            if (x == 2 || x == 3 || x == 5 || x == 7) {
                a.add(x);
            } else {
                if (x == 4) {
                    a.add(3);
                    a.add(2);
                    a.add(2);
                }
                if (x == 6) {
                    a.add(5);
                    a.add(3);
                }
                if (x == 8) {
                    a.add(7);
                    a.add(2);
                    a.add(2);
                    a.add(2);
                }
                if (x == 9) {
                    a.add(7);
                    a.add(3);
                    a.add(3);
                    a.add(2);
                }
            }
        }
        Collections.sort(a);
        for (int i = a.size() - 1; i >= 0; --i) {
            out.print(a.get(i));
        }
    }
    
    BufferedReader in;
    PrintWriter out;
    FastScanner sc;
    
    static Throwable throwable;
    
    public static void main(String[] args) throws Throwable {
        Thread thread = new Thread(null, new Solution(), "", (1 << 26));
        thread.start();
        thread.join();
        thread.run();
        if (throwable != null)
            throw throwable;
    }
    
    
    public void run() {
        try {
            //in = new BufferedReader(new FileReader(".in"));
            //out = new PrintWriter(new FileWriter(".out"));
            in = new BufferedReader(new InputStreamReader(System.in));
            out = new PrintWriter(System.out);
            sc = new FastScanner(in);
            solve();
        } catch (Exception e) {
            throwable = e;
        } finally {
            out.close();
        }
    }
}

class FastScanner {
    BufferedReader reader;
    StringTokenizer strTok;
    
    FastScanner(BufferedReader reader) {
        this.reader = reader;
    }
    
    public String nextToken() throws Exception {
        while (strTok == null || !strTok.hasMoreTokens())
            strTok = new StringTokenizer(reader.readLine());
        return strTok.nextToken();
    }
    
    public int nextInt() throws Exception {
        return Integer.parseInt(nextToken());
    }
    
    public long nextLong() throws Exception {
        return Long.parseLong(nextToken());
    }
    
    public double nextDouble() throws Exception {
        return Double.parseDouble(nextToken());
    }
}