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 Main {
    static Scanner reader;
    static int n,pow[]=new int[4];
    static int primes[]={2,3,5,7};
    static long a;
    static int g[][]=new int [4][4];
    public static void main(String[] args) throws Exception{
        reader = new Scanner(System.in);
        n=reader.nextInt();
        a=reader.nextLong();
        int i,j,k;
        for (i=0;i<4;i++) pow[i]=0;
        while (a>0){
            i=(int)(a%10); a=a/10;
            for (j=2;j<=i;j++){
                int t=j;
                if (t<=1) break;
                for (k=0;k<4;k++)
                    while (t%primes[k]==0){
                        t=t/primes[k];
                        pow[k]++;
                    }
            }
            
        }
        
        for (i=0;i<4;i++) 
            for (j=0;j<4;j++) g[i][j]=0;
        for (i=0;i<4;i++){
            for (j=2;j<=primes[i];j++){
                int t=j;
                for (k=0;k<4;k++) while  (t%primes[k]==0){
                    t=t/primes[k];
                    g[i][k]++;
                }
                
            }
        }
        for (i=3;i>=0;i--){
            for (j=0;j<pow[i];j++){
                System.out.print(primes[i]);
                for (k=0;k<i;k++) pow[k]-=g[i][k];
            }
        }
        
        
    }


}
