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.*;

public class Task implements Runnable {
    static FastScanner in;
    static PrintWriter out;

    static int[] fact = new int[10];

    static int[] res(int a) {
        a = fact[a];
        int[] res = new int[100];
        int size = 0;
        int[] pr = {7, 5, 3, 2};
        for (int i : pr) {
            while (a % fact[i] == 0) {
                res[size++] = i;
                a /= fact[i];
            }
        }
        if (a > 1) {
            throw new AssertionError();
        }
        return Arrays.copyOf(res, size);
    }

    static void solve() throws IOException {
        int n = in.nextInt();
        char[] a = in.nextToken().toCharArray();
        char[] ans = new char[100010];
        int size = 0;
        fact[0] = 1;
        for (int i = 1; i < 10; ++i) {
            fact[i] = i * fact[i - 1];
        }
        for (int i = 0; i < n; ++i) {
            int t = (int)a[i] - '0';
            for (int x : res(t)) {
                ans[size++] = (char) (x + (int) '0');
            }
        }
        ans = Arrays.copyOf(ans, size);
        Arrays.sort(ans);
        for (int i = 0; i < size / 2; ++i) {
            char t = ans[i];
            ans[i] = ans[size - 1 - i];
            ans[size - 1 - i] = t;
        }
        out.println(new String(Arrays.copyOf(ans, size)));
    }


    public void run() {
        try {
            in = new FastScanner();
            out = new PrintWriter(System.out);
            solve();
            out.close();
        } catch (IOException e) {
            e.printStackTrace();
            System.exit(1);
        }
    }

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

class FastScanner {
    BufferedReader br;
    StringTokenizer in;

    FastScanner() {
        this.br = new BufferedReader(new InputStreamReader(System.in));
    }

    FastScanner(String filename) throws FileNotFoundException {
        this.br = new BufferedReader(new FileReader(new File(filename)));
    }

    public String nextToken() throws IOException {
        while (in == null || !in.hasMoreTokens()) {
            in = new StringTokenizer(br.readLine());
        }
        return in.nextToken();
    }

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

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

    public double nextDouble() throws IOException {
        return Double.parseDouble(nextToken());
    }
}