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 com.sun.org.apache.regexp.internal.RE;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Scanner;

/**
 * Created by Nuch on 5/17/2016 AD.
 */
public class test {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        while (sc.hasNext()) {
            String lenght = sc.nextLine();
            int rel = Integer.parseInt(lenght);
            String num = sc.nextLine();

            ArrayList<Integer> ResultList = new ArrayList<>();
            int digit;

            for (int i = 0; i < rel; i++) {
                digit = Character.getNumericValue(num.charAt(i));
                if (digit == 2) {
                    ResultList.add(2);

                } else if (digit == 3) {

                    ResultList.add(3);

                } else if (digit == 4) {

                    ResultList.add(2);
                    ResultList.add(2);
                    ResultList.add(3);
                } else if (digit == 5) {

                    ResultList.add(5);

                } else if (digit == 6) {
                    ResultList.add(3);
                    ResultList.add(5);

                } else if (digit == 7) {

                    ResultList.add(7);
                    
                } else if (digit == 8) {

                    ResultList.add(2);
                    ResultList.add(2);
                    ResultList.add(2);
                    ResultList.add(7);
                } else if (digit == 9) {

                    ResultList.add(3);
                    ResultList.add(3);
                    ResultList.add(2);
                    ResultList.add(7);
                }
            }

            Collections.sort(ResultList);
            String result = "";
            for (int j = ResultList.size() - 1; j >= 0; j--) {
                result += String.valueOf(Integer.toString(ResultList.get(j)));
            }

            System.out.println(result);

        }
    }
}

    	 				 			     	  	  	   		