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.PriorityQueue;
import java.util.Scanner;

public class DrazilFactorial {

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		int n = scan.nextInt();
		scan.nextLine();
		String s = scan.nextLine();
		PriorityQueue<Integer> pq = new PriorityQueue<Integer>();
		for(int i = 0; i < n; i++){
			int x = s.charAt(i)-'0';
			if(x == 4){
				pq.add(3);
				pq.add(2);
				pq.add(2);
			}
			else if(x == 6){
				pq.add(5);
				pq.add(3);
			}
			else if(x == 8){
				pq.add(7);
				pq.add(2);
				pq.add(2);
				pq.add(2);
			}
			else if(x == 9){
				pq.add(7);
				pq.add(3);
				pq.add(3);
				pq.add(2);
			}
			else if(x != 1 && x != 0) pq.add(x);
		}
		StringBuilder ans = new StringBuilder();
		while(!pq.isEmpty()) ans.append(pq.poll());
		System.out.println(ans.reverse().toString());
	}
}
