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.*;

public class A {
    FastScanner in;
    PrintWriter out;

    public void solve() throws IOException {
        int n = in.nextInt();
        char[] s = in.next().toCharArray();
        ArrayList<Integer> ans = new ArrayList<Integer>();
        for (int i = 0; i < n; i++) {
            switch (s[i]) {
                case '0':
                case '1':
                    break;
                case '4':
                    ans.add(2);
                    ans.add(2);
                    ans.add(3);
                    break;
                case '6':
                    ans.add(5);
                    ans.add(3);
                    break;
                case '8':
                    ans.add(7);
                    ans.add(2);
                    ans.add(2);
                    ans.add(2);
                    break;
                case '9':
                    ans.add(7);
                    ans.add(3);
                    ans.add(3);
                    ans.add(2);
                    break;
                default:
                    ans.add(s[i] - '0');
            }
        }
        Collections.sort(ans, (o1, o2) -> -Integer.compare(o1, o2));
        for (int i : ans) {
            out.print(i);
        }
        out.println();
    }

    public void run() {
        try {
            in = new FastScanner(System.in);
            out = new PrintWriter(System.out);
            Locale.setDefault(Locale.US);

            solve();

            out.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    class FastScanner {
        BufferedReader br;
        StringTokenizer st;

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

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

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

    public static void main(String[] arg) {
        new A().run();
    }
}