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.*;
import java.math.*;
import java.io.*; 
 public class A{
static int sum;
static StringBuilder s;
static int gcd(int a,int b){
if(b==0)
    return a;
return gcd(b,a%b);
}
static void getdistance(String s,String t){
   
    int j=0;
    for(int i=0;i<Math.max(s.length(),t.length());i++){
        sum+=Math.abs((int)((int)s.charAt(i)-(int)(t.charAt(j))));

        j++;

//System.out.println(sum);
    }

}
 
   static void swap(int i, int j)  
{  
    
    char temp = s.charAt(i);  
    s.setCharAt(i,s.charAt(j));  
    s.setCharAt(j,temp);
     
} 
 private static void sort(long[] arr) {
        List<Long> list = new ArrayList<>();
        for (long object : arr) list.add(object);
        Collections.sort(list);
        for (int i = 0; i < list.size(); ++i) arr[i] = list.get(i);
    }
public static void main(String[] args)  throws IOException 

{
	InputReader scan=new InputReader(System.in);
  PrintWriter out=new PrintWriter(System.out);
  int n=scan.nextInt();
  String s=scan.next();
  String res="";
  for(int i=0;i<s.length();i++){
    if(s.charAt(i)=='2')
        res+="2";
    else  if(s.charAt(i)=='3')
        res+="3";
     else  if(s.charAt(i)=='4')
        res+="322";
     else  if(s.charAt(i)=='5')
        res+="5";
     else  if(s.charAt(i)=='6')
        res+="53";
     else  if(s.charAt(i)=='7')
        res+="7";
     else  if(s.charAt(i)=='8')
        res+="7222";
     else  if(s.charAt(i)=='9')
        res+="7332";
  }
  char chars[]=res.toCharArray();
  Arrays.sort(chars);
  res=new String(chars);
  res=new StringBuilder(res).reverse().toString();
  out.println(res);
 out.close();
 








 

   

}


 static class InputReader {
 
        public BufferedReader reader;
        public StringTokenizer tokenizer;
 
        public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null;
        }
 
        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }
 
        public int nextInt() {
            return Integer.parseInt(next());
        }
 
        public Double nextDouble() {
            return Double.parseDouble(next());
        }
 
        public long nextLong() {
            return Long.parseLong(next());
        }
 
        public int[] nextIntArray(int arraySize) {
            int array[] = new int[arraySize];
 
            for (int i = 0; i < arraySize; i++) {
                array[i] = nextInt();
            }
 
            return array;
        }
 
    }
static class pair implements Comparable<pair>{
	int i;
	int j;
pair(int i,int j){
	this.i=i;
	this.j=j;
} public int compareTo(pair o) {
        return j- o.j;
    }


}

}







