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.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Scanner;

 public class Main {
	 
	 /*public static int TernarySearch(int a,int b){
		 int min = a ; int max= b; 
		 for(int i=1;i<=400; i++)
		 {
			 int g= min+(max-min)/3;
			 int h = min + 2*(max-min)/3;
			 if(f(arr[h])>f(arr[g]))
				 max=h;
			 else
				 min=g;
			 
			 
			 
		 }
		 return (min+max)/2 ;
		 
		 
		 
	 }
	 
	 
	 double l = a, r = b;
 
for(int i=0; i<200; i++) {
  double l1 = (l*2+r)/3;
  double l2 = (l+2*r)/3;
  if(f(l1) > f(l2)) r = l2; else l = l1;
  }
 
x = l;
	 
	 
	 */
	 
	 
	 
	 
	 
	 
	 
	 
	
	public static void main(String  args[]){
	Scanner sc= new Scanner(System.in);
	int n=sc.nextInt(); 
	String str =sc.next(); 
String ans = "";
for(int i =0 ; i<n ;i++)
	{
		switch(str.charAt(i)){
		case '2' :ans+=("2");break ;
		case '3' :ans+=("3");break ;
		case '4' :ans+=("223");break ;
		case '5' :ans+=("5");break ;
		case '6' :ans+=("35");break ;
		case '7' :ans+=("7");break ;
		case '8' :ans+=("7222");break ;
		case '9' :ans+=("7332");break ;
		
		}
	}
char[]x = ans.toCharArray();
Arrays.sort(x);
for(int i=x.length-1; i>=0;i--)
	System.out.print(x[i]);

	
	
	
	
	
	
	}
	
	
	
 
}