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.Scanner;
import java.io.PrintStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.IOException;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 * @author hamid
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TaskC solver = new TaskC();
        solver.solve(1, in, out);
        out.close();
    }
}

class TaskC {
    public void solve(int testNumber, Scanner in, PrintWriter out) {
        int n = in.nextInt();
        String Str = in.next();
        int[] ar = new int[10];
        for (int i = 0; i < Str.length(); i++) {
            if(Str.charAt(i) == '2' || Str.charAt(i) == '3' || Str.charAt(i) == '5' || Str.charAt(i) == '7')
                ar[ Str.charAt(i) - '0' ]++;
            if(Str.charAt(i) == '4'){
                ar[2] += 2;
                ar[3]++;
            }
            if(Str.charAt(i) == '6'){
                ar[5]++;
                ar[3]++;
            }
            if(Str.charAt(i) == '8'){
                ar[7]++;
                ar[2] += 3;
            }

            if(Str.charAt(i) == '9'){
                ar[7]++;
                ar[2] += 1;
                ar[3] += 2;
            }
        }

        for (int j = 9; j >= 2 ; j--) {
            for (int k = 0; k < ar[j]; k++) System.out.print(j);
        }
    }
}
