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.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.lang.reflect.Array;
import java.util.Arrays;
import java.util.Collections;
import java.util.StringTokenizer;

public class Task515C {
    StringTokenizer st;
    PrintWriter out;
    BufferedReader in;

    public static void main(String[] args) throws IOException {
        Task515C task = new Task515C();
        task.open();
        task.solve();
        task.close();
    }


    private void close() {
        out.close();
    }

    private void solve() throws IOException {
        String[] x = {"", "", "2", "3", "322", "5", "53", "7", "7222", "7332"};
        int n = nextInt();
        char[] a = nextToken().toCharArray();
        String s = "";
        for (char c : a) {
            s = s + x[Character.getNumericValue(c)];
        }

        char[] ans = s.toCharArray();
        Arrays.sort(ans);
        for (int i = ans.length - 1; i >= 0; i--)
            out.print(ans[i]);


    }

    private void open() {
        in = new BufferedReader(new InputStreamReader(System.in));
        out = new PrintWriter(System.out);
    }

    private String nextToken() throws IOException {
        while (st == null || !st.hasMoreTokens()) {
            String line = in.readLine();
            if (line == null) return null;
            st = new StringTokenizer(line);
        }
        return st.nextToken();
    }

    private int nextInt() throws IOException {
        return Integer.parseInt(nextToken());
    }

    private long nextLong() throws IOException {
        return Long.parseLong(nextToken());
    }
}
