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 static java.util.Arrays.deepToString;

import java.io.PrintWriter;
import java.util.Arrays;
import java.util.LinkedList;
import java.util.List;
import java.util.Scanner;

public class A {

    static int N;
    PrintWriter out = new PrintWriter(System.out);

    void solve(){
        Scanner sc=new Scanner(System.in);
        N=sc.nextInt();
        long x = sc.nextLong();
        List<Integer>list =new LinkedList<>();
        while(x>0){
            int xx = (int)(x % 10);
            if(xx==4){
                list.add(2);
                list.add(2);
                list.add(3);
            } else if(xx == 6){
                list.add(5);
                list.add(3);
            } else if(xx==8){
                list.add(2);
                list.add(2);
                list.add(2);
                list.add(7);
            } else if(xx==9){
                list.add(2);
                list.add(3);
                list.add(3);
                list.add(7);
            } else if(xx>1){
                list.add(xx);
            }
            x/=10;
        }
        Integer[] a = list.toArray(new Integer[]{});
        Arrays.sort(a);
        StringBuilder sb=new StringBuilder();
        for (int i = 0; i < a.length; i++) {
            sb.append(a[a.length-i-1]);
            System.out.print(a[a.length-i-1]);
        }
        System.out.println();
    }

    long f(long a){
        long res = 1;
       
        while(a > 0){
            long x = a%10;
            a/=10;
            res *= fact[(int)x];
        }
        return res;
    }
    int[] fact;
    void run(){
        fact = new int[10];
        fact[0]=fact[1]=1;
        for (int i = 2; i < fact.length; i++) {
            fact[i] = fact[i-1]*i;
        }

        solve();
        out.flush();
        
    }
    public static void main(String[] args) {
        new A().run();
    }
    static int NI(){
        try {
            int c=System.in.read(),r=0;
            for(;c!='-'&&(c<'0'||'9'<c);)c=System.in.read();
            if(c=='-') return -NI();
            for(;'0'<=c&&c<='9';c=System.in.read())
                r = r * 10 + c - '0';
            return r;
        } catch (Exception e) {
            return -1;
        }
    }
    void debug(Object...os) {
        System.err.println(deepToString(os));
    }
}
