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.math.*;

public class mayn {
	
	
	
	public static void main(String[] args) {
		
		Scanner scan = new Scanner (System.in);
		int n = scan.nextInt();
		String x = scan.next();
		int [] fac = {1,1,2,6,24,120,720,5040,40320,362880};
		int [] used = {0,0,0,0,0,0,0,0,0,0};
		int total = 0;
		for (int i=0 ; i<n ; i++) {
			char c = x.charAt(i);
			int k = c - '0';
			used[k]++;
		}
		//ArrayList<Integer> bestnumber = new ArrayList<>();
		used[2] += used[9] + 3*used[8] + 2*used[4];
		used[3] += 2*used[9] + used[6] + used[4];
		used[5] += used[6];
		used[7] += used[9] + used[8];
		used[4] = 0;
		used[6] = 0;
		used[8] = 0;
		used[9] = 0;
		for (int i=7 ; i>1 ; i--) {
			for (int j=0 ; j<used[i] ; j++) {
				System.out.print(i);
			}
		}
	}
	
}