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

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 * @author Anudeep Nekkanti
 */
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);
		TaskA solver = new TaskA();
		solver.solve(1, in, out);
		out.close();
	}
}

class TaskA {
    public void solve(int testNumber, Scanner in, PrintWriter out) {
        int n = in.nextInt();
        long x = in.nextLong();
        int [] count = new int[10];
        for (int i = 0; i < 10; i++) {
            count[i] = 0;
        }
        long tx = x;
        while(tx > 0) {
            int cur = (int)(tx % 10);
            tx /= 10;
            if(cur == 2 || cur == 3) {
                count[cur]++;
            }
            if(cur == 4) {
                count[2] += 2;
                count[3] += 1;
            }
            if(cur == 5) {
                count[cur]++;
            }
            if(cur == 6) {
                count[3]++;
                count[5]++;
            }
            if(cur == 7) {
                count[cur]++;
            }
            if(cur == 8) {
                count[7]++;
                count[2] += 3;
            }
            if(cur == 9) {
                count[3] += 2;
                count[2]++;
                count[7]++;
            }
        }

        String ans = "";
        for (int i = 9; i > 1; i--) {
            while(count[i] > 0) {
                count[i]--;
                ans = ans.concat("" + (char)('0' + i));
            }
        }
        out.println(ans);
    }
}

