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.List;
import java.util.Scanner;
import java.io.OutputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Collections;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 * @author thnkndblv
 */
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();
        char[] s = in.next().toCharArray();

        ArrayList<Integer> arr = new ArrayList<Integer>();
        for (char c : s) {
            switch ( c ) {
                case '0':
                case '1': continue;
                case '2': arr.add( 2 ); break;
                case '3': arr.add( 3 ); break;
                case '4': arr.add( 2 ); arr.add( 2 ); arr.add( 3 ); break;
                case '5': arr.add( 5 ); break;
                case '6': arr.add( 3 ); arr.add( 5 ); break;
                case '7': arr.add( 7 ); break;
                case '8': arr.add( 2 ); arr.add( 2 ); arr.add( 2 ); arr.add( 7 ); break;
                case '9': arr.add( 3 ); arr.add( 3 ); arr.add( 2 ); arr.add( 7 );
            }
        }

        Collections.sort( arr );
        Collections.reverse( arr );

        for (int x : arr) out.print( x );
        out.println();
    }
}
