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.InputStreamReader;
import java.io.PrintWriter;
import java.util.*;
import java.util.function.Function;
import java.util.function.ToDoubleFunction;
import java.util.function.ToIntFunction;
import java.util.function.ToLongFunction;

public class P_515C{
    static class Compare implements Comparator<Character>{
        @Override
        public int compare(Character o1, Character o2){
            return o1-o2;
        }
    }
    public static void main(String[] args){
        FS sc = new FS();
        PrintWriter pw = new PrintWriter(System.out);
        int n = sc.nextInt();
        String num = sc.next();
        HashMap<Character, String> map = new HashMap<>(){{
            put('2',"2");
            put('3',"3");
            put('4',"322");
            put('5',"5");
            put('6',"53");
            put('7',"7");
            put('8',"7222");
            put('9',"7332");
        }};
        StringBuilder sb = new StringBuilder();
        for(int i=0; i<num.length(); i++){
            if(num.charAt(i)!='0' && num.charAt(i)!='1'){
                sb.append(map.get(num.charAt(i)));
            }
        }
        char[] c = sb.toString().toCharArray();
        Arrays.sort(c);
        sb = new StringBuilder("");
        for(int i=c.length-1; i>=0; i--)
            sb.append(c[i]+"");
        System.out.println(sb.toString());
        pw.flush();
        pw.close();
    }

    static class FS{
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st = new StringTokenizer("");

        String next(){
            while(!st.hasMoreElements()){
                try{
                    st = new StringTokenizer(br.readLine());
                } catch(Exception ignored){
                }
            }
            return st.nextToken();
        }

        int[] nextArray(int n){
            int[] a = new int[n];
            for(int i = 0; i < n; i++){
                a[i] = nextInt();
            }
            return a;
        }

        long[] nextLongArray(int n){
            long[] a = new long[n];
            for(int i = 0; i < n; i++){
                a[i] = nextLong();
            }
            return a;
        }

        int nextInt(){
            return Integer.parseInt(next());
        }

        long nextLong(){
            return Long.parseLong(next());
        }

        double nextDouble(){
            return Double.parseDouble(next());
        }
    }
}
