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 java.math.*;


public class Main implements Runnable {
    static BufferedReader in;
    static PrintWriter out;
    static StringTokenizer tok;
    
    
    static void solve() throws Exception {
        int[] f = new int[10];
        f[0] = 1;
        for (int i = 1; i <= 9; ++i) {
            f[i] = f[i - 1] * i;
        }
        List<Integer>[] dp = new ArrayList[f[9] + 1];
        for (int i = 0; i <= f[9]; ++i) {
            dp[i] = new ArrayList<Integer>();
        }
        dp[1].add(1);
        for (int i = 2; i <= 9; ++i) {
            for (int j = 1; (long)j * f[i] <= f[9]; ++j) {
                if (!dp[j].isEmpty()) {
                    int j2 = j * f[i];
                    if (dp[j2].size() < dp[j].size() + 1) {
                        dp[j2].clear();
                        for (int k = 0; k < dp[j].size(); ++k) {
                            dp[j2].add(dp[j].get(k));
                        }
                        dp[j2].add(i);
                    }
                }
            }
        }
        int n = nextInt();
        char[] s = next().toCharArray();
        List<Integer> ans = new ArrayList<Integer>();
        for (int i = 0; i < n; ++i) {
            if (s[i] > '1') {
                for (int j = 1; j < dp[f[s[i]  - '0']].size(); ++j) {
                    ans.add(dp[f[s[i]  - '0']].get(j));
                }
            }
        }
        Collections.sort(ans);
        for (int i = (int)ans.size() - 1; i >= 0; --i) {
            out.print(ans.get(i));
        }
        out.println();
    }
    
    static int nextInt() throws IOException {
        return Integer.parseInt(next());
    }

    static long nextLong() throws IOException {
        return Long.parseLong(next());
    }

    static double nextDouble() throws IOException {
        return Double.parseDouble(next());
    }

    static BigInteger nextBigInteger() throws IOException {
        return new BigInteger(next());
    }
    
    static String next() throws IOException {
        while (tok == null || !tok.hasMoreTokens()) {
            tok = new StringTokenizer(in.readLine());
        }
        return tok.nextToken();
    }
    
    static String nextLine() throws IOException {
        tok = new StringTokenizer("");
        return in.readLine();
    }

    static boolean hasNext() throws IOException {
        while (tok == null || !tok.hasMoreTokens()) {
            String s = in.readLine();
            if (s == null) {
                return false;
            }
            tok = new StringTokenizer(s);
        }
        return true;
    }
    
    public static void main(String args[]) {
        new Thread(null, new Main(), "Main", 1 << 28).start();
    }
    
    public void run() {
        try {
            in = new BufferedReader(new InputStreamReader(System.in));
            out = new PrintWriter(new OutputStreamWriter(System.out));
            //in = new BufferedReader(new FileReader("input.in"));
            //out = new PrintWriter(new FileWriter("output.out"));
            Locale.setDefault(Locale.US);
            solve();
            in.close();
            out.close();
        } catch (Throwable e) {
            e.printStackTrace();
            java.lang.System.exit(1);
        }
    }
}