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.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map.Entry;
import java.util.Scanner;
import java.util.Set;
import java.util.TreeSet;


@SuppressWarnings("unused")
public class A {
	public  static  Scanner scan = new Scanner(System.in);
	public static void solve () {
		 int n=scan.nextInt(); 
		 String s=scan.next();
		 String t="";
		 for(int i=0;i<n;i++) {
			 if(s.charAt(i)=='0' || s.charAt(i)=='1') {
				 continue;
			 }
			 else {
				 if(s.charAt(i)=='2')t+='2';
				 else if(s.charAt(i)=='3')t+=3;
				 else if(s.charAt(i)=='4')t+=322;
				 else if(s.charAt(i)=='5')t+=5;
				 else if(s.charAt(i)=='6')t+=53;
				 else if(s.charAt(i)=='7')t+=7;
				 else if(s.charAt(i)=='8')t+=7222;
				 else t+=7332;
			 }
		 }
		 char[] y=t.toCharArray();
		 Arrays.sort(y);
		for (int i = y.length-1; i >=0; i--) {
			System.out.print(y[i]);
		}
	}
	
	public static void main(String[] args) {
	
		solve();
		scan.close();
	}

}

