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.*;
import java.util.Scanner;
import java.util.StringTokenizer;


public class A
{
    public static void main(String[] args) throws IOException
    {
        Scanner in = new Scanner(System.in);

        int n = in.nextInt();
        char [] input = in.next().toCharArray();

        int [] have = new int[10];
        for(char i : input)
        {
            int dig = i - '0';
            if(dig <= 1)
                continue;

            for(int j = 2 ; j <= dig ; j++)
            {
                int tmp = j;
                for(int k = 2 ; k <= tmp ; k++)
                    while(tmp % k == 0)
                    {
                        tmp /= k;
                        have[k]++;
                    }
            }
        }

        for(int i = 9 ; i >= 2 ; i--)
            while(have[i] > 0)
            {
                if(i == 7)
                {
                    have[7]--;
                    have[3]--;have[2]--;
                    have[5]--;
                    have[2]--;have[2]--;
                    have[3]--;
                    have[2]--;
                    System.out.print(7);
                }
                else if(i == 5)
                {
                    have[5]--;
                    have[2]--;have[2]--;
                    have[3]--;
                    have[2]--;
                    System.out.print(5);
                }
                else if(i == 3)
                {
                    have[3]--;
                    have[2]--;
                    System.out.print(3);
                }
                else if(i == 2)
                {
                    have[2]--;
                    System.out.print(2);
                }
            }

        System.out.println();

    }
}