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.*;
import java.io.*;

public class factorial {
	public void run() throws Exception {
		Scanner file = new Scanner(System.in);
		int times = file.nextInt();
		int[] x = Arrays.stream(file.next().split("")).mapToInt(n -> Integer.parseInt(n)).toArray();
		ArrayList<Integer> xx = new ArrayList();
		for (int i = 0; i < x.length; i++) {
			int w = x[i];
			if (w == 2 || w == 3 || w == 5 || w == 7) xx.add(w);
			else if (w == 4) {
				xx.add(3); xx.add(2); xx.add(2);
			}
			else if (w == 6) {
				xx.add(5); xx.add(3);
			}
			else if (w == 8) {
				xx.add(7); xx.add(2); xx.add(2); xx.add(2);
			}
			else if (w == 9){
				xx.add(7); xx.add(3); xx.add(3); xx.add(2);
			}
		}
		Collections.sort(xx); Collections.reverse(xx);
		for (int i : xx) System.out.print(i);
	}

	public static void main(String[] args) throws Exception {
		new factorial().run();
	}

}