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.*;


public class C_292 {
    
    public static void main(String a[])
    {
        Scanner inp = new Scanner(System.in);
        
        String s = inp.nextLine();
        s = inp.nextLine();
        Operation ops = new Operation();
        
        char output[];
        try
        {
        ops.output(s);
        }
        catch(Exception e)
        {
            e.printStackTrace();
            return;
        }
        
        
    }

}

class Operation 
{
    public void output(String s)
    {
        String ou ="";
        
        
        for(int i=0;i<s.length();i++)
        {
            int t= s.charAt(i)-'0';
            
            if(t==0 ||t ==1)
                continue;
            else if(t==2||t==3||t==5||t==7)
                ou = ou+ t;
            else if(t==4)
            {
                ou = ou+"322";
            }
            else if(t==6)
            {
                ou = ou+"53";
            }
            else if(t==8)
                ou = ou+"7222";
            else if(t==9)
                ou = ou+"7332";
            
            
        }
        
        char []out = ou.toCharArray();
        //System.out.println(out.length);
        
        
        for(int i=0;i<out.length;i++)
        {
            for(int j=i+1;j<out.length;j++)
            {
                if(out[i]<out[j])
                {
                    char temp=out[i];
                    out[i]=out[j];
                    out[j]=temp;
                }
            }
            System.out.print(out[i]);
        }
        
        System.out.println();
                
    }
    }
