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.Arrays;
import java.util.Scanner;

public class A {

    void run(){
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        char[] s = sc.next().toCharArray();
        int[] primes = new int[10];
        int[] p = {2, 3, 5, 7};
        for(char ch:s){
            int x = ch-'0';
            for(int j=2;j<=x;j++){
                int y = j;
                for(int i=0;i<4;i++){
                    int prime = p[i];
                    while(y%prime==0){
                        primes[prime]++;
                        y/=prime;
                    }
                }
            }
        }
        String ans = "";
        for(;;){
            int max = 1;
            while(true){
                if(ok(primes, max+1))max++;
                else break;
            }
            if(max==1)break;
            if(7 <= max)max=7;
            else if(5<=max)max=5;
            else if(3<=max)max=3;
            for(int j=2;j<=max;j++)sub(primes, j);
            ans+=max;
        }
        System.out.println(ans);
    }
    
    boolean ok(int[] c, int x){
        if(x==2)return 1 <= c[2];
        if(x==3)return 1 <= c[3];
        if(x==4)return 2 <= c[2];
        if(x==5)return 1 <= c[5];
        if(x==6)return 1 <= c[2] && 1 <= c[3];
        if(x==7)return 1 <= c[7];
        if(x==8)return 3 <= c[8];
        if(x==9)return 2 <= c[2];
        return false;
    }
    
    void sub(int[] c, int x){
        if(x==2){
            c[2]--;return;
        }else if(x==3){
            c[3]--; return;
        }else if(x==4){
            c[2]-=2; return;
        }else if(x==5){
            c[5]--; return;
        }else if(x==6){
            c[2]--; c[3]--; return;
        }else if(x==7){
            c[7]--; return;
        }else if(x==8){
            c[2]-=3; return;
        }else c[3]-=2;
        
    }
    
    void debug(Object...o){
        System.out.println(Arrays.deepToString(o));
    }
    
    public static void main(String[] args) {
        new A().run();
    }
}   