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.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Collections;


public class A292 {

    public static void main(String[] args) throws IOException {
        BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
        
        String s=br.readLine();
        s=br.readLine();
        
        ArrayList<Integer> ans=new ArrayList<>();
        
        for(int i=0;i<s.length();i++){
            if(s.charAt(i)=='0'){

            }else if(s.charAt(i)=='1'){

            }else if(s.charAt(i)=='2'){
                ans.add(2);
            }else if(s.charAt(i)=='3'){
                ans.add(3);
            }else if(s.charAt(i)=='4'){
                ans.add(3);
                ans.add(2);
                ans.add(2);
            }else if(s.charAt(i)=='5'){
                ans.add(5);
            }else if(s.charAt(i)=='6'){
                ans.add(5);
                ans.add(3);
            }else if(s.charAt(i)=='7'){
                ans.add(7);
            }else if(s.charAt(i)=='8'){
                ans.add(7);
                ans.add(2);
                ans.add(2);
                ans.add(2);
            }else if(s.charAt(i)=='9'){
                ans.add(7);
                ans.add(2);
                ans.add(3);
                ans.add(3);
            }
        }
        
        Collections.sort(ans);
        
        for(int i=ans.size()-1;i>=0;i--){
            System.out.print(ans.get(i));
        }
        System.out.println();
    }
}
