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.Scanner;

/**
 * Created with IntelliJ IDEA.
 * User: vio
 * Date: 28.02.2015
 * Time: 1:39
 */
public class DrazilC {
    
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = Integer.parseInt(in.nextLine());
        char a[] = in.nextLine().toCharArray();
        int d[] = new int[8];
        for (char c : a) {
            for (int j = c - '0'; j > 1; j--) {
                switch (j){
                    case 2: d[2]++; break;
                    case 3: d[3]++; break;
                    case 4: d[2] += 2; break;
                    case 5: d[5]++; break;
                    case 6: d[2]++; d[3]++; break;
                    case 7: d[7]++; break;
                    case 8: d[2] += 3; break;
                    case 9: d[3] += 2; break;
                }
            }
        }
        //System.out.println(Arrays.toString(d));
        StringBuilder res = new StringBuilder();
        for(int i = 7; i > 1; i--) {
            while (d[i] > 0) {
                for (int j = i; j > 1; j--) {
                    switch (j){
                        case 2: d[2]--; break;
                        case 3: d[3]--; break;
                        case 4: d[2] -= 2; break;
                        case 5: d[5]--; break;
                        case 6: d[2]--; d[3]--; break;
                        case 7: d[7]--; break;
                        case 8: d[2] -= 2; break;
                        case 9: d[3] -= 2; break;
                    }
                }
                res.append(i);
            }
        }
        String r = res.toString();
        System.out.println(r.isEmpty() ? "1" : r);
    }
}
