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.*;
import java.util.*;
import java.lang.*;

public class Rextester{
    public static void main(String[] args)throws IOException{
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        int n = new Integer(br.readLine());
        char[] num=br.readLine().toCharArray();
        br.close();
        int four=0,eight=0,one=0,p=0,six=0,nine=0;
        for(int i=0;i<num.length;i++){
            if(num[i]=='4'){
                four+=2;
            }
            else if(num[i]=='8'){
                eight+=3;
            }
            else if(num[i]=='1'||num[i]=='0'){
                one++;
            }
            else if(num[i]=='6'){
                six+=1;
            }
            else if(num[i]=='9'){
                nine+=3;
            }
        }
        
        int[] array = new int[num.length+four+eight+six+nine-one];
        Arrays.fill(array,0);
        for(int i=0;i<num.length;i++){
            if(num[i]=='1'||num[i]=='0'){}
            else if(num[i]=='4'){
                array[p++]=2;
                array[p++]=2;
                array[p++]=3;
            }
            else if(num[i]=='8'){
                array[p++]=7;
                array[p++]=2;
                array[p++]=2;
                array[p++]=2;
            }
            else if(num[i]=='6'){
                array[p++]=3;
                array[p++]=5;
            }
            else if(num[i]=='9'){
                array[p++]=7;
                array[p++]=3;
                array[p++]=3;
                array[p++]=2;
            }
            else{
                array[p++]=((int)num[i]-'0');
            }
        }
        Arrays.sort(array);
        for(int i=array.length-1;i>=0;i--){
            System.out.print(array[i]);
        }
    }
}

            